All these USB version names. I used to know what they all meant, but then the USB IF went ahead and renamed them all and made a bunch of versions have the same name and renamed some versions to have the same name as the old name of other versions.
I have absolutely no idea what anyone means when they say USB 3.2 gen 2x2. I used to know what USB 3.2 meant but it's certainly not that.
Unfortunately "USB 3.2" is just a version of the standard, which does not give any information about the performance of a USB port or device.
USB 5 Gb/s = USB 3.2 gen 1, available on Type A or Type C connectors (or on devices on a special extended micro B connector)
USB 10 Gb/s = USB 3.2 gen 2, available on Type A or Type C connectors
USB 20 Gb/s = USB 3.2 gen 2x2, available only on Type C connectors
Moreover, "5 Gb/s" is a marketing lie. The so-called USB of 5 Gb/s has a speed of 4 Gb/s (the same as PCIe 2.0). On the other hand, 10 Gb/s and 20 Gb/s, have the claimed speeds, so USB of 10 Gb/s is 2.5 times faster than USB of 5 Gb/s, not 2 times faster.
10 Gb/s USB and Ethernet have truly the same speed, but the USB overhead is somewhat higher, leading to a somewhat lower speed. However, the speed shown in TFA, not much higher than 7 Gb/s seems too low, and it may be caused by the Windows drivers. It is possible that on other operating systems, e.g. Linux, one can get a higher transfer speed.
USB is just a complete mess. I don't mind so much ports having different capabilities if they are well documented in the specification sheets of the hardware because then at least I can find out what they are capable of, but alas it never seems to be the case. Its very hard to work out whether a port can do Displayport and to what extent/performance or its true power capability or just its real data transfer speed. More often than I like I have just hoped that something works. Anything above 5W charging and 5gbps transfer is optional.
The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't.
It probably looks the same no matter what, and the cable selected to use probably also won't be very forthcoming with its capabilities either.
The USB A connector stayed the same between USB 1, 2 and 3. Yet most manufacturers voluntary distinguished them by giving USB 1 and 1.1 a white insert in plug and port, USB 2 a black insert and USB 3 a blue one
This was neither standarized nor enforced, yet it worked remarkably well in the real world
Then we decided to just have no markings at all on USB C cables. On the ports at least we occasionally get little thunderbolt or power symbols
Going by Fabien Sanglard's cheat sheet (who I trust uncritically) https://fabiensanglard.net/usbcheat/index.html it looks like 3.2 actually is a broader term than expected. Maybe there was some awful attempt at backwards compatibility? Or forwards?
Great site, thanks for the link. But holy heck, that "Also Known As" column is complete chaos. What the heck is wrong with the USB Consortium, do they have brain damage?
Also, according to that table, "USB4 Gen 2×2" is a downgrade on "USB 3.2 Gen 2x2", since the cable length is 0.8m instead of 1m for the same speeds. Which is uhh unexpected.
To be fair they seem to have taken this often-stated criticism on board. USB 4's naming is more sensible, and they've pushed the simple data speed & power labelling that makes it easier to work out what you need.
I predict in future when our civilization will advance to higher level, this phenomenon will happen with english words and jargons. e.g. here are versioned and namespaced words. topology.bio.23, topology.math.45 etc.
Welcome to the brave new world we will enter in far future.
I'm still curious why it can't reach full 10GbE in both directions. Afaik USB gen 3.2 2x2 the transmit and receive directions are independent. So it doesn't really make sense to reach full speed one way and not the other way, purely from a USB perspective.
100 mode saved me once when I really really really needed to have a connection in that moment, but the ethernet cable glued to the wall that I was using had only three out of eight wires even functioning.
> how does [100BASE-TX] save power vs [1000BASE-T] running at low throughput?
100BASE-TX uses just two pairs (lanes), one for sending and one for receiving. 1000BASE-T uses all four pairs, for both sending and receiving. Therefore, a 100BASE-TX interface that's only receiving needs to power up one pair. A 1000BASE-T interface needs to power all four pairs all the time.
I recall reading about some extensions that allow switching off some of the pairs some of the time ("Green Ethernet"), but I think that they require support on both sides of the link, and I'm not sure if they are widely deployed.
Isn’t that only relevant for network topologies that rely heavily on broadcasting to multiple nodes. Eg token ring, WiFi and powerline adapters?
For regular Ethernet, the switch will have a table of which IPs are on which NIC and thus can dynamically send packets at the right transmission protocols supported by those NICs without degrading the service of other NICs.
I’ve seen some vlans hit 1mbit BUM filters, I think we had about 800 users on that one. To saturate a 10m link would require a help of a lot of broadcast traffic.
100m is fine. 10m is fine but I can’t think of anything that negotiates 10m other than maybe WOL (I don’t use it enough to be sure from memory).
If I didn ahve something esoteric it would be on a specialised vlan anyway.
Is that really true? If so, is there a saner way to handle this than upgrade all the things to 10GBE? Like a POE ethernet condom that interfaces with both network and devices at native max speeds without the core network having to degrade?
Are there any that actually have a SFP+ port? That's all I want. No one wants to use 10g ethernet when DACs are cheaper than cat7, and you can just change it up to a $7 multimode when you need longer runs.
Modern transceivers can do 10G on absolutely garbage twisted pair. My house was wired with absolutely dire cat5 cabling. Zero shielding and barely any copper in the pairs. I thought I'd barely be able to do 1G on them, but modern transceivers (amazon) easily do 10G over like 30M of that sort of cables.
In fact I had more trouble getting quality fiber working for that sort of distance than El Cheapo cat5. They do heat up a bit, but they work wonder.
10G DACs are no cheaper than cat6, which is perfectly fine for 10G at most practical distances. Considering the target audience of these cards it seems pretty obvious to me that letting users "just buy a cat 6 cable" is miles more reasonable than having them buy a transceiver or DAC.
As for allowing to switch to fiber, that just seems orthogonal again to what these USB NICs are for, not to mention the SFP+ itself is probably more expensive than the NIC shown here...
DACs are very cheap (second hand and AliExpress) and they never use much W. If both machines are near each other though (which a DAC cable implies) and both run Linux and both support Thunderbolt, you might be better off with a direct ethernet over TB connection. Whether macOS supports such, I don't know.
The other side will then also need a low power NIC (of which fiber and DAC over SFP+ are less power hungry). What this article doesn't mention, is that there are also a lot of PCIe NICs on the market which aren't power hungry (RTL8127), as well as RTL8261C for switches/routers.
I've seen low power RTL NICs with SFP+ on it, too (example: [1]). With SFP+, you'll have a lot more versatility. DAC and SFP+ fiber are very cheap, btw. Especially second hand they go for virtually nothing. I have 10 SFP+ fiber lying around here doing nothing which I got for a few EUR each.
For me as European with high energy prices and solar energy gotten the beat next year (in NL), this is all very interesting.
There's a couple of good reasons why to opt for fiber in the home. You keep the energy between the different groups separated which can help. I also find fiber very easy to get through walls, allowing me to have multiple fiber connections through walls (currently I use 1x fiber + 1x ethernet for PoE possibilities from fusebox).
With all above being said, AQC100S is low power and does not get very hot. You can get these with SFP+ and PCIe/TB. They've been available for a while.
10 GbE sits in a really weird spot for me, maybe I'm just not understanding something though. It's at most 1.25 GB/sec of bandwidth, yet it's relatively quite expensive. It's not sufficient bandwidth for getting good performance out of most SSDs, yet it's really excessive for any hard drives (except for RAID10 setups I guess). For SSDs you want thunderbolt (or 40+ GbE) connection for best latency and performance, and for hard drives 2.5Gbit/sec is more than enough. As I said, I might be misunderstanding something, but 10 GbE sits between the two sensible options for me.
10 Gb is cheap! Mikrotik has a 4x10Gb + 1x1Gb port switch for $150 USD and an 8x10Gb version for about $275. I have the 8 port version.
SFP+'s and fiber are cheap, like maybe 50 bucks for the SFP+ set and fiber. 10Gb PCIe cards are maybe ~$50 new on Amazon with Intel chips and cheaper on eBay - I bought used 10 Gb Mellanox cards for $25 each - "they just work" under FreeBSD and Linux.
Copper 10 Gb used to consume waaaaay more power (like 5+W per port!) and cost more both in terms of the SFP and cable. In reality fiber is more environmentally friendly as there is no copper, less energy used, and less plastic per meter. So my setup mostly consists of SR and BR optics and DAC's. The "DAC" direct attach cables are handy for switch-switch or short switch<->NIC runs. And I will continue to run fiber for the foreseeable future and actively avoid copper.
Exactly. Enough supports 10gbe that you might as well grab it; a few Mikrotik switches, some old enterprise gear, and an adapter gets you some good speeds.
Sure some of it might have been fine at 2.5 or 5 but those are relatively new and less commonly available.
I'm actually surprised at the amount of 2.5/5 gear I've been coming across lately, especially in the 2.5 space as more ISPs are pushing for gigabit+ to the house.
Verizon's been issuing a wireless router with 10G WAN and several 2.5G ports and MoCA support that includes a 2.5G adapter and they use that across all their current connection types. I was delighted to see that when I got the router a couple years ago.
~ 1 GB/sec seems about right for a long time. I can't imagine the basic files I work with everyday getting much more storage-dense than they are in 2026.
Making a long distance complex network may be expensive, but to connect directly a few computers one can use 25 Gb/s Ethernet at a reasonable price.
Last time when I checked, dual-port 25 Gb/s NICs were not much more expensive than dual-port 10 Gb/s NICs.
If you have a few computers with no more than a few meters distance between them, you can put a dual-port 25 Gb/s card in each and connect them directly with direct attach copper cables, in a daisy chain or in a ring, without an expensive switch.
No, of course I'm not going to if I choose thunderbolt :). But in many cases it's fine because SSDs aren't nearly as noisy as HDDs, so the NAS can just sit under your desk.
For 40+ GbE or fibre I agree they are expensive, but at least you get full performance out of your system. SSDs aren't cheap these days either...
I gotta say, I love my macbooks. Every Apple laptop I've owned that has USB-C ports will happily charge itself from a 5V/1.5A wall charger (albeit extremely slowly).
That hasn’t been my experience. I once tried to charge an M3 MBP via a lower powered wall plug. It was left off over night and the following morning the battery was still at 1%.
My work has a little power strip with a usb-c and usb-a jack on it at every desk. I can charge my phone and iPad just fine with a USB-C cable into the USB-C port, but when I plugged my MacBook Air into it, it says “not charging.” Going into the system information tool I can see it’s only running at 10W. So apparently 10W is not enough to charge, but it’s still at least keeping the battery from draining.
A 20w charger will definitely charge the MacBook, just slowly.
This was a decent USB plug from Anker. I regularly use it to charge things like iPhones and tablets. I knew it wouldn’t supply enough power to run the MBP but thought it should trickle charge the device over night. But it didn’t.
I can’t recall which cable I used though. The cable might have been garbage but I’m pretty sure I threw out all the older USB cables so they wouldn’t get mixed with more modern supporting cables.
They probably require higher voltages but I havent seen one myself. I usually just charge y laptop with my phone charger, what is it, 18 watts? Don't care, charges my laptop and the phone that is plugged into it overnight. Why charge at faster speeds when there is no need to
My laptop refuses to charge for 45W chargers as well, but I can almost understand it.
When plugged into 100W chargers while powered on, it takes ten minutes to gain a single percentage point. Idle in power save may let me charge the thing in a few hours. If I start playing video, the battery slowly drains.
If your laptop is part space heater, like most laptops with Nvidia GPUs in them seem to be, using a low power adapter like that is pretty useless.
Also, 100W chargers are what, 25 euros these days? An OEM charger costs about 120 so the USB-C plan still works out.
Other manufacturers do similar things. Apple accepts lower wattage chargers (because that's what they sell themselves) but they ignore two power negotiation standards and only supports the very latest, which isn't in many affordable chargers, limiting the fast charge capacity for third parties.
Which laptop is that? My Razer with 5070 will take 45W chargers just fine, so do the ThinkPads, my work 16" MacBook and previous Asus Zephyrus with 4070.
I was on a trip a few years ago and had only brought my “compact” 45w usb-c charger since the brick that came with my work ThinkPad (one of the high end 16” screen models, maybe p16?) was enormous. When I plugged it in Windows complained that the charger was insufficient to charge the laptop. I think it at least kept it from draining the battery though. I had to run to Walmart and get a 65w charger which did the job fine.
Coincidentally, the USB-C spec is written such that wattage implies a minimum set of supported voltages:
* ≤15W charger: must have 5V
* ≤27W charger: must have 5V & 9V
* ≤45W charger: must have 5V & 9V & 15V
* (OT but worth noting: >60W: requires "chipped" cable.)
* ≤100W charger: must have 5V & 9V & 15V & 20V
(levels above this starting to become relevant for the new 240W stuff)
(36W/12V doesn't exist anymore in PD 3.0. There seems to be a pattern with 140W @ 28V now, and then 240W at 48V, I haven't checked what's actually in the specs now for those, vs. what's just "herd agreement".)
Some devices are built to only charge from 20V, which means you need to buy a 45.000001W (scnr) charger to be sure it'll charge. If I remember correctly, requiring a minimum wattage to charge is permitted by the standard, so if the device requires a 46W charger it can assume it'll get 15V. Not sure about what exactly the spec says there, though.
(Of course the chargers may support higher voltages at lower power, but that'd cost money to build so they pretty much don't.)
NB: the lower voltages are all mandatory to support for higher powered chargers to be spec compliant. Some that don't do that exist — they're not spec compliant.
This has nothing to do with USB-C, this is the minimum design voltage of your lithium ion battery pack. In this case, you have a 4-cell pack, and if the cells drop below 2.895V that means they're physically f*cked and HP would like to sell you a new battery. (Sometimes that can be fixed by trickle charging, depending on how badly f*cked the battery is.)
If your laptop's USB-C circuitry were built for it, you could charge it from 5V. (Slowly, of course.) It's not even that much of a stretch given laptops are built with "NVDC"¹ power systems, and any charger input goes into a buck-boost voltage regulator anyway.
With 802.3bt type 4 (71W delivered, 90W consumed), absolutely achievable with the proper electronics, but would you trust a no-name, fly-by-night NIC to not fry your expensive devices? That's the biggest hurdle. Possibly a company like Apple, Anker, or similar megacorp or high-trust startup could pull if off.
PoE can be cheap, but usually never cheaper than non-poe. But if you have a PoE switch and spare ports, its very nice.
The problem comes when you try to design a large network and need random PoE ports on end devices where you can't home-run a cable back.
I have a Unifi Pro XG 48 PoE and I love it, but I still don't use PoE for everything. The cost of a (non unifi) poe device + the cost of using one of those ports always exceeds a simple power adapter on the other side (if possible).
TFA doesn't compare the performance of the new adapters with the older ones.
Does anyone know if the old bulky ones will hit 10G speeds on the same hardware?
I assume I can get a few old TB2 models and adapters on the cheap and they'll run cool enough and stable enough for constant 1G internet and occasional 10G intranet
For Thunderbolt 4/5 docks, I've held off from buying a high-end Thunderbolt 5 dock as many still have 2.5GbE Ethernet and other limitations with displays. The CalDigit TS5 Plus is one of the only options with 10GbE and its $500 (and usually OoS). I managed to buy an ex-corporate refurb HP Thunderbolt 4 G4 dock for only ~$64 and would recommend others do the same (this has an Intel 2.5GbE and good display outputs)
I don't understand how a 10GbE adapter is possible without Thunderbolt, or why not being Thunderbolt makes it smaller. In my experience USB speeds faster than 3 don't happen in practice unless you have a Thunderbolt port and device. Maybe I just don't have devices that use the faster USB speeds, but Thunderbolt has always been the one and only way to exceed the speed of USB for me.
I think USB 4 exists based on the Thunderbolt spec (or the other way around?), but doesn't require any Thunderbolt capabilities and therefore isn't very telling.
I think Apple's approach of supporting Thunderbolt 4/5 on every USB port of the MacBook Pro is the only sustainable way forward.
What you're seeing are the speeds of various multi-tier caches (RAM, intermediate SLC etc.) It cannot write to its main flash memory that fast. While it to the user looks as if they just wrote 10 GiB in a single second, the SSD is internally still busy for another 10 seconds persisting that data. The actual real write speed of top-shelf consumer grade SSDs these days is somewhere in the vicinity of 1.5 GiB/s. Most models top out at half of that or less.
I bought this one when upgrading my desktop, it indeed delivers what it promises. 14.5GB/s on my tiny random desktop, it's impressive. Everything feels so instantaneous, my Linux desktop finally feels like a Mac :)
I have one of these, though I'm using with a USB 3.x port as that's what my desktop has. For me it's working fine, and for others with actual USB 4 ports it seems to be working properly for them.
You can find 2.5G switches with a reasonable amount of ports on the cheap. For 10G though the cost is still prohibitive IMHO unless you are fine with 2 ports.
For cables, I think everything converged to cat6a a while ago, which is both reasonably cheap and perfecrly fine for 10G (up to 100m from what I remember)
Mikrotik has a couple 4-5 port 10 GbE switches (one has SFP+ ports, one has RJ45), and Ubiquiti has a couple small switches now that don't quite break the bank at least.
/*
* RealTek 8129/8139 PCI NIC driver
*
* Supports several extremely cheap PCI 10/100 adapters based on
* the RealTek chipset. Datasheets can be obtained from
* www.realtek.com.tw.
*
* Written by Bill Paul <wpaul@ctr.columbia.edu>
* Electrical Engineering Department
* Columbia University, New York City
/
/
* The RealTek 8139 PCI NIC redefines the meaning of 'low end.' This is
* probably the worst PCI ethernet controller ever made, with the possible
* exception of the FEAST chip made by SMC. The 8139 supports bus-master
* DMA, but it has a terrible interface that nullifies any performance
* gains that bus-master DMA usually offers.
*
* For transmission, the chip offers a series of four TX descriptor
* registers. Each transmit frame must be in a contiguous buffer, aligned
* on a longword (32-bit) boundary. This means we almost always have to
* do mbuf copies in order to transmit a frame, except in the unlikely
* case where a) the packet fits into a single mbuf, and b) the packet
* is 32-bit aligned within the mbuf's data area. The presence of only
* four descriptor registers means that we can never have more than four
* packets queued for transmission at any one time.
*
* Reception is not much better. The driver has to allocate a single large
* buffer area (up to 64K in size) into which the chip will DMA received
* frames. Because we don't know where within this region received packets
* will begin or end, we have no choice but to copy data from the buffer
* area into mbufs in order to pass the packets up to the higher protocol
* levels.
*
* It's impossible given this rotten design to really achieve decent
* performance at 100Mbps, unless you happen to have a 400Mhz PII or
* some equally overmuscled CPU to drive it.
*
* On the bright side, the 8139 does have a built-in PHY, although
* rather than using an MDIO serial interface like most other NICs, the
* PHY registers are directly accessible through the 8139's register
* space. The 8139 supports autonegotiation, as well as a 64-bit multicast
* filter.
*
* The 8129 chip is an older version of the 8139 that uses an external PHY
* chip. The 8129 has a serial MDIO interface for accessing the MII where
* the 8139 lets you directly access the on-board PHY registers. We need
* to select which interface to use depending on the chip type.
*/
Those comments are about the 25 years old RTL8139, among the world's first highly affordable and fully-integrated Fast Ethernet controllers that ended up on pretty much every motherboard. Contrary to all of the aged complaints about the RTL8139, I ran several such on OpenBSD (and Windows) for close to ten years with no problems at all.
I've had such terrible success with usb-ethernet adapters on linux, to the point where wifi is usually much more performant. The main issue is connection drops. You can see it easily in gnome where the ethernet connection constantly drops and comes back up. It's so frequent though that even scp-ing a medium-sized file is likely to fail or stall. Hardware is a Framework 13 3rd gen laptop.
Is this just my hardware? It's hard to imagine these issues would be so prevalent with how many people use these on linux...
> The main issue is connection drops. You can see it easily in gnome where the ethernet connection constantly drops and comes back up.
I never ever saw that and I'm literally using usb-to-ethernet adapters on Linux since forever. It's about the chipset you're using and how the kernel supports it no? For example for 2.5 Gbit/s ethernet if you go with anything with a Realtek RTL8156B (and not the older non 'B') or anything more recent it should work flawlessly.
Before buying I look on the Internet for users' returns / kernel support what the latest chipset the cool kids on the block are using.
As I've been perfectly happy with Realtek 8156B for 2.5 Gbit/s if I wanted to buy a 10 Gbit/s one, I'd look at cool kids, like that Jeff Geerling dude from TFA/Youtube, and see he's using a Realtek 8159 and I'd think: "Oh that's close to mine, I trust that to work very well".
I literally still even have an old USB2.0-to-100Mbit/s that I use daily and that has never failed me neither (it's for an old laptop that I use as some kind of terminal over SSH). I don't recommend 100 Mbit/s: my point is that it's been many moons all this has flawless support under Linux.
> Is this just my hardware?
To me it's due to a poor chipset / poor chipset support in the USB-to-ethernet adapter you're using.
These things, when they're a well supported chipset, are flawless.
I am definitely not the person to shed any light on what is going on, but you've added to my feeling that these adapters are all incomprehensible, so I'll try and do the same for you.
I have a USB C ethernet adapter (a Belkin USB-C to Ethernet + Charge Adapter which I recommend if you need it). I ran out of USB C ports one day, and plugged it through a USB C to USB A adapter instead. I must have done an fast.com speed-test to make sure it wasn't going to slow things down drastically, and found that the latency was lower! Not a huge amount, and I think the max speed was quicker without the adapter. But still, lower latency through a $1.50 Essager USB C to USB A adapter, bought from Shein or Shopee or somewhere silly!
I tried tons of times, back and forward, with the adapter a few times, then without the adapter a few times. Even on multiple laptops. As much as I don't want to, I keep seeing lower latency through this cheap adapter.
Next step, I'll try USB C to USB A, then back through a USB A to USB C adapter. Who knows how fast my internet could be!
Will they be cheaper? I look at the RAM prices. Granted,
RAM is in a different category than USB adapters, but
I no longer trust anyone writing "will be cheaper" -
the reality may be different to the projection made.
Too bad this is 10Gbase-T, that energy-wasting hot-running garbage needs to die sooner rather than later. Good thing the ranges for 25Gbase-T are short enough to make it impractical for home use.
(Fibre is nowhere near as "sensitive" as some people believe.)
The problem with fibre isn't the sensitivity. It's that most endpoints have a 1Gbps copper port on them and then Cat6A ports can be used with the common devices but also allow you to add or relocate 10Gbps devices without rewiring the building again.
You've been able to get Intel X520 NICs [0], with transceivers included for ~40USD on Newegg for a long time. This is a little more than double the price of Newegg's cheapest single-port 10/100/1000 copper card, but even the cheapest available such card is three times your "chicken and egg"-solving price point.
I suspect the combination of the absence of cheap-o all-in-one AP/router combo boxes with any SFP+ cages and fiber cabling's reputation of being extremely fragile have much more to do with its scarcity at the extremely low end of networking gear than anything else.
Ymmv. I've got a mix of cheap premade patch cables and some I crimped from solid core, all cat5e, all holding 10gbe totally happily. I suspect that only works because they're a meter or two long but that reaches across the rack.
It's inherently worse than anything fibre, or even DAC cables (which are kinda cheating.) It needs a shitton of analog "magic" to work with the bandwidth limitations of copper cabling.
All these USB version names. I used to know what they all meant, but then the USB IF went ahead and renamed them all and made a bunch of versions have the same name and renamed some versions to have the same name as the old name of other versions.
I have absolutely no idea what anyone means when they say USB 3.2 gen 2x2. I used to know what USB 3.2 meant but it's certainly not that.
Unfortunately "USB 3.2" is just a version of the standard, which does not give any information about the performance of a USB port or device.
USB 5 Gb/s = USB 3.2 gen 1, available on Type A or Type C connectors (or on devices on a special extended micro B connector)
USB 10 Gb/s = USB 3.2 gen 2, available on Type A or Type C connectors
USB 20 Gb/s = USB 3.2 gen 2x2, available only on Type C connectors
Moreover, "5 Gb/s" is a marketing lie. The so-called USB of 5 Gb/s has a speed of 4 Gb/s (the same as PCIe 2.0). On the other hand, 10 Gb/s and 20 Gb/s, have the claimed speeds, so USB of 10 Gb/s is 2.5 times faster than USB of 5 Gb/s, not 2 times faster.
10 Gb/s USB and Ethernet have truly the same speed, but the USB overhead is somewhat higher, leading to a somewhat lower speed. However, the speed shown in TFA, not much higher than 7 Gb/s seems too low, and it may be caused by the Windows drivers. It is possible that on other operating systems, e.g. Linux, one can get a higher transfer speed.
USB is just a complete mess. I don't mind so much ports having different capabilities if they are well documented in the specification sheets of the hardware because then at least I can find out what they are capable of, but alas it never seems to be the case. Its very hard to work out whether a port can do Displayport and to what extent/performance or its true power capability or just its real data transfer speed. More often than I like I have just hoped that something works. Anything above 5W charging and 5gbps transfer is optional.
Oh, it's fine.
The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't.
It probably looks the same no matter what, and the cable selected to use probably also won't be very forthcoming with its capabilities either.
(Be sure to drink your Ovaltine.)
The USB A connector stayed the same between USB 1, 2 and 3. Yet most manufacturers voluntary distinguished them by giving USB 1 and 1.1 a white insert in plug and port, USB 2 a black insert and USB 3 a blue one
This was neither standarized nor enforced, yet it worked remarkably well in the real world
Then we decided to just have no markings at all on USB C cables. On the ports at least we occasionally get little thunderbolt or power symbols
This quagmire (along with the version names) is why I call it the Unintuitive Serial Bus.
Going by Fabien Sanglard's cheat sheet (who I trust uncritically) https://fabiensanglard.net/usbcheat/index.html it looks like 3.2 actually is a broader term than expected. Maybe there was some awful attempt at backwards compatibility? Or forwards?
Great site, thanks for the link. But holy heck, that "Also Known As" column is complete chaos. What the heck is wrong with the USB Consortium, do they have brain damage?
Also, according to that table, "USB4 Gen 2×2" is a downgrade on "USB 3.2 Gen 2x2", since the cable length is 0.8m instead of 1m for the same speeds. Which is uhh unexpected.
To be fair they seem to have taken this often-stated criticism on board. USB 4's naming is more sensible, and they've pushed the simple data speed & power labelling that makes it easier to work out what you need.
Yeah, now it's USB4 Version 2.0 / USB 80Gbps / USB4 Gen4.
I don't think they've taken the criticism on board, USB 3 still has the completely nonsensical names
I predict in future when our civilization will advance to higher level, this phenomenon will happen with english words and jargons. e.g. here are versioned and namespaced words. topology.bio.23, topology.math.45 etc.
Welcome to the brave new world we will enter in far future.
I'm still curious why it can't reach full 10GbE in both directions. Afaik USB gen 3.2 2x2 the transmit and receive directions are independent. So it doesn't really make sense to reach full speed one way and not the other way, purely from a USB perspective.
A Framework expansion card was also announced this week. https://frame.work/nl/en/products/wisdpi-10g-ethernet-expans...
That link notes:
"Card supports 10Gbit/s and 10/100/1000/2500/5000/10000Mbit/s Ethernet"
Nice to see; some NICs are shedding 10/100 support. Apparently, it's not necessary to do this, even in a low cost device.
100 mode saved me once when I really really really needed to have a connection in that moment, but the ethernet cable glued to the wall that I was using had only three out of eight wires even functioning.
Don’t we need at least four for 100 Mbps?
According to the technician I spoke with, he could only detect three on their end.
The cable was chewed through by cats, so perhaps it was three just in that moment.
The connection was overall unreliable, so I guess it must have been four, just not all of the time.
There is two wire ethernet that supports 100. It isn't common, but automotive is starting to use it.
Low-cost devices are exactly where 10/100 is still widely used. On PCs, it's a common power-saving mode.
TVs too.
And PoE security cams.
For those of us who don’t know, how does it save power vs a 1gbe running at low throughput?
> how does [100BASE-TX] save power vs [1000BASE-T] running at low throughput?
100BASE-TX uses just two pairs (lanes), one for sending and one for receiving. 1000BASE-T uses all four pairs, for both sending and receiving. Therefore, a 100BASE-TX interface that's only receiving needs to power up one pair. A 1000BASE-T interface needs to power all four pairs all the time.
I recall reading about some extensions that allow switching off some of the pairs some of the time ("Green Ethernet"), but I think that they require support on both sides of the link, and I'm not sure if they are widely deployed.
I assume it is for wake-on-LAN. This of course requires the NIC being powered on while the system is sleeping. Lower bandwidth mode = less power draw.
100 is needed for embedded stuff, it'd render a lot of devices unusable (wiznet chips are popular and are 100 only). That'd suck.
There are plenty of embedded chips which only provide RMII. No RGMII or alternatives.
Lots of industrial sensors and devices only do 4 wire 100BASE-TX so if there's no fallback to that it would be a paperweight in those situations.
-
That hasn't been true on switched networks in probably 20 years or so.
Isn’t that only relevant for network topologies that rely heavily on broadcasting to multiple nodes. Eg token ring, WiFi and powerline adapters?
For regular Ethernet, the switch will have a table of which IPs are on which NIC and thus can dynamically send packets at the right transmission protocols supported by those NICs without degrading the service of other NICs.
I’ve seen some vlans hit 1mbit BUM filters, I think we had about 800 users on that one. To saturate a 10m link would require a help of a lot of broadcast traffic.
100m is fine. 10m is fine but I can’t think of anything that negotiates 10m other than maybe WOL (I don’t use it enough to be sure from memory).
If I didn ahve something esoteric it would be on a specialised vlan anyway.
We have switches now, hubs just don't exist anymore. Switches are not affected by some devices having a lower speed.
Is that really true? If so, is there a saner way to handle this than upgrade all the things to 10GBE? Like a POE ethernet condom that interfaces with both network and devices at native max speeds without the core network having to degrade?
> Is that really true?
It's not, cf. sibling posts. The GP probably learned networking in the 80ies~90ies when it was true, but those times are long gone.
(unless you're talking wifi.)
That is complete nonsense and not how switched networks work.
A Framework SFP+ or SFP28 expansion would be sweet.
Are there any that actually have a SFP+ port? That's all I want. No one wants to use 10g ethernet when DACs are cheaper than cat7, and you can just change it up to a $7 multimode when you need longer runs.
The SFP+ ones are all Thunderbolt or USB4 this far, i.e. not backward compatible with USB 3.x, like this QNAP one: https://www.qnap.com/en/product/qna-uc10g1sf
Modern transceivers can do 10G on absolutely garbage twisted pair. My house was wired with absolutely dire cat5 cabling. Zero shielding and barely any copper in the pairs. I thought I'd barely be able to do 1G on them, but modern transceivers (amazon) easily do 10G over like 30M of that sort of cables.
In fact I had more trouble getting quality fiber working for that sort of distance than El Cheapo cat5. They do heat up a bit, but they work wonder.
10G DACs are no cheaper than cat6, which is perfectly fine for 10G at most practical distances. Considering the target audience of these cards it seems pretty obvious to me that letting users "just buy a cat 6 cable" is miles more reasonable than having them buy a transceiver or DAC.
As for allowing to switch to fiber, that just seems orthogonal again to what these USB NICs are for, not to mention the SFP+ itself is probably more expensive than the NIC shown here...
DACs are very cheap (second hand and AliExpress) and they never use much W. If both machines are near each other though (which a DAC cable implies) and both run Linux and both support Thunderbolt, you might be better off with a direct ethernet over TB connection. Whether macOS supports such, I don't know.
The other side will then also need a low power NIC (of which fiber and DAC over SFP+ are less power hungry). What this article doesn't mention, is that there are also a lot of PCIe NICs on the market which aren't power hungry (RTL8127), as well as RTL8261C for switches/routers.
I've seen low power RTL NICs with SFP+ on it, too (example: [1]). With SFP+, you'll have a lot more versatility. DAC and SFP+ fiber are very cheap, btw. Especially second hand they go for virtually nothing. I have 10 SFP+ fiber lying around here doing nothing which I got for a few EUR each.
For me as European with high energy prices and solar energy gotten the beat next year (in NL), this is all very interesting.
There's a couple of good reasons why to opt for fiber in the home. You keep the energy between the different groups separated which can help. I also find fiber very easy to get through walls, allowing me to have multiple fiber connections through walls (currently I use 1x fiber + 1x ethernet for PoE possibilities from fusebox).
With all above being said, AQC100S is low power and does not get very hot. You can get these with SFP+ and PCIe/TB. They've been available for a while.
[1] https://nl.aliexpress.com/item/1005011733192115.html (no vouching for, just first hit on search)
10 GbE sits in a really weird spot for me, maybe I'm just not understanding something though. It's at most 1.25 GB/sec of bandwidth, yet it's relatively quite expensive. It's not sufficient bandwidth for getting good performance out of most SSDs, yet it's really excessive for any hard drives (except for RAID10 setups I guess). For SSDs you want thunderbolt (or 40+ GbE) connection for best latency and performance, and for hard drives 2.5Gbit/sec is more than enough. As I said, I might be misunderstanding something, but 10 GbE sits between the two sensible options for me.
I have a zfs x 3 disk hard drive mirror and 10GbE.
For writes yes 10GbE overkill but for for reads it's faster than 2.5GbE would be.
Sure there is 5GbE but most switches that support 5GbE support 10GbE.
10 Gb is cheap! Mikrotik has a 4x10Gb + 1x1Gb port switch for $150 USD and an 8x10Gb version for about $275. I have the 8 port version.
SFP+'s and fiber are cheap, like maybe 50 bucks for the SFP+ set and fiber. 10Gb PCIe cards are maybe ~$50 new on Amazon with Intel chips and cheaper on eBay - I bought used 10 Gb Mellanox cards for $25 each - "they just work" under FreeBSD and Linux.
Copper 10 Gb used to consume waaaaay more power (like 5+W per port!) and cost more both in terms of the SFP and cable. In reality fiber is more environmentally friendly as there is no copper, less energy used, and less plastic per meter. So my setup mostly consists of SR and BR optics and DAC's. The "DAC" direct attach cables are handy for switch-switch or short switch<->NIC runs. And I will continue to run fiber for the foreseeable future and actively avoid copper.
10gbe is a sweet spot at least for my homelab stuff. It's easy to find old enterprise gear for, cheap, and fast enough for everything I want to do.
Exactly. Enough supports 10gbe that you might as well grab it; a few Mikrotik switches, some old enterprise gear, and an adapter gets you some good speeds.
Sure some of it might have been fine at 2.5 or 5 but those are relatively new and less commonly available.
I'm actually surprised at the amount of 2.5/5 gear I've been coming across lately, especially in the 2.5 space as more ISPs are pushing for gigabit+ to the house.
Verizon's been issuing a wireless router with 10G WAN and several 2.5G ports and MoCA support that includes a 2.5G adapter and they use that across all their current connection types. I was delighted to see that when I got the router a couple years ago.
I chose 10GbE to fit 20 HDDs in RAID 10.
~ 1 GB/sec seems about right for a long time. I can't imagine the basic files I work with everyday getting much more storage-dense than they are in 2026.
Are you gonna run thunderbolt more than a few meters? If you think 10 is expensive, check prices above 10. You may even need fiber for that.
Making a long distance complex network may be expensive, but to connect directly a few computers one can use 25 Gb/s Ethernet at a reasonable price.
Last time when I checked, dual-port 25 Gb/s NICs were not much more expensive than dual-port 10 Gb/s NICs.
If you have a few computers with no more than a few meters distance between them, you can put a dual-port 25 Gb/s card in each and connect them directly with direct attach copper cables, in a daisy chain or in a ring, without an expensive switch.
No, of course I'm not going to if I choose thunderbolt :). But in many cases it's fine because SSDs aren't nearly as noisy as HDDs, so the NAS can just sit under your desk.
For 40+ GbE or fibre I agree they are expensive, but at least you get full performance out of your system. SSDs aren't cheap these days either...
Is it also possible to power a laptop through those adapters? PoE++ can deliver up to 100W of power, more than enough for most laptops.
Theoretically yes, practically that hasn't been built yet. I've only seen it for 2.5Gbase-T, and only for 802.3bt Type 3 (51W).
If anyone's aware of something better, I'd be interested too :)
(Then again I wouldn't voluntarily use 5Gb-T or 10Gb-T anyway, and ≈50W is enough for most use cases.)
[ed.: https://www.aliexpress.us/item/3256807960919319.html ("2.5GPD2CBT-20V" variant) - actually 2.5G not 1G as I wrote initially]
Eh.
A lot of laptops won't accept less than 60w
My work laptop won't accept less than 90w (A modern HP, i7 155h with a random low end GPU)
At first everyone at the office just assumed that the USB C wasn't able to charge the pc
I gotta say, I love my macbooks. Every Apple laptop I've owned that has USB-C ports will happily charge itself from a 5V/1.5A wall charger (albeit extremely slowly).
That hasn’t been my experience. I once tried to charge an M3 MBP via a lower powered wall plug. It was left off over night and the following morning the battery was still at 1%.
Note:
Some devices expect USB-A on the charger side instead of C
USB-A pump out 1A5V(5W) regardless of what's connected to it, then it negotiate higher power if available.
USB C-C does not give any power if the receiving device is not able to negotiate it
My work has a little power strip with a usb-c and usb-a jack on it at every desk. I can charge my phone and iPad just fine with a USB-C cable into the USB-C port, but when I plugged my MacBook Air into it, it says “not charging.” Going into the system information tool I can see it’s only running at 10W. So apparently 10W is not enough to charge, but it’s still at least keeping the battery from draining.
A 20w charger will definitely charge the MacBook, just slowly.
This was a decent USB plug from Anker. I regularly use it to charge things like iPhones and tablets. I knew it wouldn’t supply enough power to run the MBP but thought it should trickle charge the device over night. But it didn’t.
I can’t recall which cable I used though. The cable might have been garbage but I’m pretty sure I threw out all the older USB cables so they wouldn’t get mixed with more modern supporting cables.
What did it start at?
1%
They probably require higher voltages but I havent seen one myself. I usually just charge y laptop with my phone charger, what is it, 18 watts? Don't care, charges my laptop and the phone that is plugged into it overnight. Why charge at faster speeds when there is no need to
Laptop charges fine regular 5V as well.
My Thinkpad T490 will happily take any power provided voltage is high enough (15V+).
Great. So we got EU laws to mandate USB-C chargers and then get manufacturers that flaunt the spirit of the law by rejecting lower wattages.
My laptop refuses to charge for 45W chargers as well, but I can almost understand it.
When plugged into 100W chargers while powered on, it takes ten minutes to gain a single percentage point. Idle in power save may let me charge the thing in a few hours. If I start playing video, the battery slowly drains.
If your laptop is part space heater, like most laptops with Nvidia GPUs in them seem to be, using a low power adapter like that is pretty useless.
Also, 100W chargers are what, 25 euros these days? An OEM charger costs about 120 so the USB-C plan still works out.
Other manufacturers do similar things. Apple accepts lower wattage chargers (because that's what they sell themselves) but they ignore two power negotiation standards and only supports the very latest, which isn't in many affordable chargers, limiting the fast charge capacity for third parties.
Which laptop is that? My Razer with 5070 will take 45W chargers just fine, so do the ThinkPads, my work 16" MacBook and previous Asus Zephyrus with 4070.
I was on a trip a few years ago and had only brought my “compact” 45w usb-c charger since the brick that came with my work ThinkPad (one of the high end 16” screen models, maybe p16?) was enormous. When I plugged it in Windows complained that the charger was insufficient to charge the laptop. I think it at least kept it from draining the battery though. I had to run to Walmart and get a 65w charger which did the job fine.
A Mac mini at home used 4.64w averaged over the last 30 days. Even under load it just sips power.
It can draw a lot more under load? https://support.apple.com/en-gb/103253
The issue might not be the wattage bit rather the minimum voltage. (Some?) Macs seems to charge at 15v already, most laptops need 20v
Coincidentally, the USB-C spec is written such that wattage implies a minimum set of supported voltages:
* ≤15W charger: must have 5V
* ≤27W charger: must have 5V & 9V
* ≤45W charger: must have 5V & 9V & 15V
* (OT but worth noting: >60W: requires "chipped" cable.)
* ≤100W charger: must have 5V & 9V & 15V & 20V
(levels above this starting to become relevant for the new 240W stuff)
(36W/12V doesn't exist anymore in PD 3.0. There seems to be a pattern with 140W @ 28V now, and then 240W at 48V, I haven't checked what's actually in the specs now for those, vs. what's just "herd agreement".)
Some devices are built to only charge from 20V, which means you need to buy a 45.000001W (scnr) charger to be sure it'll charge. If I remember correctly, requiring a minimum wattage to charge is permitted by the standard, so if the device requires a 46W charger it can assume it'll get 15V. Not sure about what exactly the spec says there, though.
(Of course the chargers may support higher voltages at lower power, but that'd cost money to build so they pretty much don't.)
NB: the lower voltages are all mandatory to support for higher powered chargers to be spec compliant. Some that don't do that exist — they're not spec compliant.
My laptop has
And I can charge it via USB-C using a 22.5W powerbank @ 12V (HP EliteBook 845 G10.)I guess that would be out of spec then?
edit: nvm I didn't see the qualifier 'minimum'
If your laptop's USB-C circuitry were built for it, you could charge it from 5V. (Slowly, of course.) It's not even that much of a stretch given laptops are built with "NVDC"¹ power systems, and any charger input goes into a buck-boost voltage regulator anyway.
¹ google "NVDC power", e.g. https://www.monolithicpower.com/en/learning/resources/batter... (scroll down to it)
Most laptops will take 45W. There might be some workstations that don't, but even gaming stuff with 5080s will charge on 45W.
Somewhat, there are a few expensive "PoE to Data + Power" adapters out there
https://www.procetpoe.com/poe-usb-converter/ (some of these are power-only)
The idea of a POE Mac mini makes me happy. It would be a nice way of power cycling it from the switch, tidier than the smart plug I have.
https://hackaday.com/2023/08/14/adding-power-over-ethernet-s...
It's undoubtably a cool solution, but in why do you need to remotely do a hard power cycle? Won't just SSHing in and rebooting be enough?
And when ssh is down because you OOMd or something else?
I don't really run heavy loads on my home server, so I haven't thought of that
Makes sense, thanks!
I can’t find what you want, but you can buy PoE splitters. PoE in, ethernet and power out.
Surely a matter of time until someone does this…
I found a 5gbe one that claimed 60W, will power a phone but not the low power laptop I've got here. It probably isn't far off.
We used PoE hats for a bunch of Raspberry Pis once. It’s definitely a great idea.
PoE Texas sells the most compatible adapters for this use.
https://shop.poetexas.com/products/gbt-usbc-pd-usbc?variant=...
65W 802.3bt and gigabit Ethernet out on the same PD cable.
Also a crude fixed hub for data and a keyboard and mouse for docking laptops:
https://shop.poetexas.com/products/bt-usbc-a-pd?variant=3938...
I think class 4 tops out at about 71W delivered to the powered device, albeit 90W at the switch port.
Might be a struggle I suspect!
With 802.3bt type 4 (71W delivered, 90W consumed), absolutely achievable with the proper electronics, but would you trust a no-name, fly-by-night NIC to not fry your expensive devices? That's the biggest hurdle. Possibly a company like Apple, Anker, or similar megacorp or high-trust startup could pull if off.
Yes, but look up the prices for PoE switches and you might reconsider.
PoE can be cheap, but usually never cheaper than non-poe. But if you have a PoE switch and spare ports, its very nice.
The problem comes when you try to design a large network and need random PoE ports on end devices where you can't home-run a cable back.
I have a Unifi Pro XG 48 PoE and I love it, but I still don't use PoE for everything. The cost of a (non unifi) poe device + the cost of using one of those ports always exceeds a simple power adapter on the other side (if possible).
I think about this a lot.
FWIW I got a Xikestor 10G adapter with the Realtek chipset from AliExpress and it underperforms my much cheaper 5G one.
Yeah. Just because it negotiates, doesn’t mean it can utilise.
I have a 5G USB and getting it to work at 5G speeds in Linux was a challenge. The driver worked properly only with kernel 6.12 not 6.10 nor 6.14
TFA doesn't compare the performance of the new adapters with the older ones.
Does anyone know if the old bulky ones will hit 10G speeds on the same hardware?
I assume I can get a few old TB2 models and adapters on the cheap and they'll run cool enough and stable enough for constant 1G internet and occasional 10G intranet
My favorite USB ethernet adapter is a lowly 100 MBit one that works everywhere without requiring driver downloads.
For Thunderbolt 4/5 docks, I've held off from buying a high-end Thunderbolt 5 dock as many still have 2.5GbE Ethernet and other limitations with displays. The CalDigit TS5 Plus is one of the only options with 10GbE and its $500 (and usually OoS). I managed to buy an ex-corporate refurb HP Thunderbolt 4 G4 dock for only ~$64 and would recommend others do the same (this has an Intel 2.5GbE and good display outputs)
I don't understand how a 10GbE adapter is possible without Thunderbolt, or why not being Thunderbolt makes it smaller. In my experience USB speeds faster than 3 don't happen in practice unless you have a Thunderbolt port and device. Maybe I just don't have devices that use the faster USB speeds, but Thunderbolt has always been the one and only way to exceed the speed of USB for me.
I think USB 4 exists based on the Thunderbolt spec (or the other way around?), but doesn't require any Thunderbolt capabilities and therefore isn't very telling.
I think Apple's approach of supporting Thunderbolt 4/5 on every USB port of the MacBook Pro is the only sustainable way forward.
What cat cable works with it?
The PCIe version: https://news.ycombinator.com/item?id=46423967
Can any of them do TSN?
wow. Maybe i should try it
It seems like a lot of laptop manufacturers skipped the USB 3.2 Gen2x2 in favor of USB4/TB4.
Conversely, the last time I checked a couple of weeks ago, it was impossible to find any USB4 external SSDs on Amazon; only USB 3.2.
Wouldn't it be better to just buy an M.2 NVMe adapter, eg. ICY DOCK ICYNano MB861U31-1M2B[0]?
[0]: https://global.icydock.com/product_247.html
That doesn't seem to be USB 4?
Is there an SSD that saturates USB3.2 Gen2 speeds and requires USB4?
Maybe not, but the USB consortium hasn't got around to polluting the USB4 namespace yet so it's safer to buy stuff with the USB4 label.
Of course, just give them some time and they'll come up with USB4 "gen classic" at 11 Mbps.
Oh yes. Samsung 9100 Pro does 14800/13400 MiB/s over PCIe 5x4.
What you're seeing are the speeds of various multi-tier caches (RAM, intermediate SLC etc.) It cannot write to its main flash memory that fast. While it to the user looks as if they just wrote 10 GiB in a single second, the SSD is internally still busy for another 10 seconds persisting that data. The actual real write speed of top-shelf consumer grade SSDs these days is somewhere in the vicinity of 1.5 GiB/s. Most models top out at half of that or less.
I bought this one when upgrading my desktop, it indeed delivers what it promises. 14.5GB/s on my tiny random desktop, it's impressive. Everything feels so instantaneous, my Linux desktop finally feels like a Mac :)
Many PCIe4 or 5 drives
If Amazon is a strict requirement, then this won't help. But if you're ok with AliExpress then it's probably a win:
https://www.aliexpress.com/item/1005008555989592.html
I have one of these, though I'm using with a USB 3.x port as that's what my desktop has. For me it's working fine, and for others with actual USB 4 ports it seems to be working properly for them.
Really? I see plenty when I search for 'usb4 nvme enclosure'
By the way, how are switches and cables for > 1Gbps these days?
You can find 2.5G switches with a reasonable amount of ports on the cheap. For 10G though the cost is still prohibitive IMHO unless you are fine with 2 ports.
For cables, I think everything converged to cat6a a while ago, which is both reasonably cheap and perfecrly fine for 10G (up to 100m from what I remember)
Mikrotik has a couple 4-5 port 10 GbE switches (one has SFP+ ports, one has RJ45), and Ubiquiti has a couple small switches now that don't quite break the bank at least.
From the source of the RealTek 8129/8139 PCI NIC driver in FreeBSD: (old, not directly relevant, just amusing) https://elixir.bootlin.com/freebsd/v10.2/source/sys/pci/if_r...
/* * RealTek 8129/8139 PCI NIC driver * * Supports several extremely cheap PCI 10/100 adapters based on * the RealTek chipset. Datasheets can be obtained from * www.realtek.com.tw. * * Written by Bill Paul <wpaul@ctr.columbia.edu> * Electrical Engineering Department * Columbia University, New York City / / * The RealTek 8139 PCI NIC redefines the meaning of 'low end.' This is * probably the worst PCI ethernet controller ever made, with the possible * exception of the FEAST chip made by SMC. The 8139 supports bus-master * DMA, but it has a terrible interface that nullifies any performance * gains that bus-master DMA usually offers. * * For transmission, the chip offers a series of four TX descriptor * registers. Each transmit frame must be in a contiguous buffer, aligned * on a longword (32-bit) boundary. This means we almost always have to * do mbuf copies in order to transmit a frame, except in the unlikely * case where a) the packet fits into a single mbuf, and b) the packet * is 32-bit aligned within the mbuf's data area. The presence of only * four descriptor registers means that we can never have more than four * packets queued for transmission at any one time. * * Reception is not much better. The driver has to allocate a single large * buffer area (up to 64K in size) into which the chip will DMA received * frames. Because we don't know where within this region received packets * will begin or end, we have no choice but to copy data from the buffer * area into mbufs in order to pass the packets up to the higher protocol * levels. * * It's impossible given this rotten design to really achieve decent * performance at 100Mbps, unless you happen to have a 400Mhz PII or * some equally overmuscled CPU to drive it. * * On the bright side, the 8139 does have a built-in PHY, although * rather than using an MDIO serial interface like most other NICs, the * PHY registers are directly accessible through the 8139's register * space. The 8139 supports autonegotiation, as well as a 64-bit multicast * filter. * * The 8129 chip is an older version of the 8139 that uses an external PHY * chip. The 8129 has a serial MDIO interface for accessing the MII where * the 8139 lets you directly access the on-board PHY registers. We need * to select which interface to use depending on the chip type. */
> unless you happen to have a 400Mhz PII or some equally overmuscled CPU to drive it
Oh no!
Those comments are about the 25 years old RTL8139, among the world's first highly affordable and fully-integrated Fast Ethernet controllers that ended up on pretty much every motherboard. Contrary to all of the aged complaints about the RTL8139, I ran several such on OpenBSD (and Windows) for close to ten years with no problems at all.
8159 != 8139
> /* * RealTek 8129/8139 PCI NIC driver * * Supports several extremely cheap PCI 10/100 adapters based on […]
Also, please, for the love of whatever entity, at least remove the *s on that paste. This is just atrocious and disrespectful of any reader.
I've had such terrible success with usb-ethernet adapters on linux, to the point where wifi is usually much more performant. The main issue is connection drops. You can see it easily in gnome where the ethernet connection constantly drops and comes back up. It's so frequent though that even scp-ing a medium-sized file is likely to fail or stall. Hardware is a Framework 13 3rd gen laptop.
Is this just my hardware? It's hard to imagine these issues would be so prevalent with how many people use these on linux...
> The main issue is connection drops. You can see it easily in gnome where the ethernet connection constantly drops and comes back up.
I never ever saw that and I'm literally using usb-to-ethernet adapters on Linux since forever. It's about the chipset you're using and how the kernel supports it no? For example for 2.5 Gbit/s ethernet if you go with anything with a Realtek RTL8156B (and not the older non 'B') or anything more recent it should work flawlessly.
Before buying I look on the Internet for users' returns / kernel support what the latest chipset the cool kids on the block are using.
As I've been perfectly happy with Realtek 8156B for 2.5 Gbit/s if I wanted to buy a 10 Gbit/s one, I'd look at cool kids, like that Jeff Geerling dude from TFA/Youtube, and see he's using a Realtek 8159 and I'd think: "Oh that's close to mine, I trust that to work very well".
I literally still even have an old USB2.0-to-100Mbit/s that I use daily and that has never failed me neither (it's for an old laptop that I use as some kind of terminal over SSH). I don't recommend 100 Mbit/s: my point is that it's been many moons all this has flawless support under Linux.
> Is this just my hardware?
To me it's due to a poor chipset / poor chipset support in the USB-to-ethernet adapter you're using.
These things, when they're a well supported chipset, are flawless.
I have a RTL8157 5 Gbps adapter from CableMatters.
Interestingly it seems to get burning hot on the MacBook M1 Pro while it remains cool on the M5 Pro model.
Maybe the workload is different, but I would not rule out some sort of hardware or driver difference. I only use a 1G port on my router at the moment.
Huh! That's very interesting.
I am definitely not the person to shed any light on what is going on, but you've added to my feeling that these adapters are all incomprehensible, so I'll try and do the same for you.
I have a USB C ethernet adapter (a Belkin USB-C to Ethernet + Charge Adapter which I recommend if you need it). I ran out of USB C ports one day, and plugged it through a USB C to USB A adapter instead. I must have done an fast.com speed-test to make sure it wasn't going to slow things down drastically, and found that the latency was lower! Not a huge amount, and I think the max speed was quicker without the adapter. But still, lower latency through a $1.50 Essager USB C to USB A adapter, bought from Shein or Shopee or somewhere silly!
I tried tons of times, back and forward, with the adapter a few times, then without the adapter a few times. Even on multiple laptops. As much as I don't want to, I keep seeing lower latency through this cheap adapter.
Next step, I'll try USB C to USB A, then back through a USB A to USB C adapter. Who knows how fast my internet could be!
> USB 3.2 Gen 2x1
What the fuck
Will they be cheaper? I look at the RAM prices. Granted, RAM is in a different category than USB adapters, but I no longer trust anyone writing "will be cheaper" - the reality may be different to the projection made.
Too bad this is 10Gbase-T, that energy-wasting hot-running garbage needs to die sooner rather than later. Good thing the ranges for 25Gbase-T are short enough to make it impractical for home use.
(Fibre is nowhere near as "sensitive" as some people believe.)
The problem with fibre isn't the sensitivity. It's that most endpoints have a 1Gbps copper port on them and then Cat6A ports can be used with the common devices but also allow you to add or relocate 10Gbps devices without rewiring the building again.
However — unlike copper twisted pair — the bandwidth current fiber media can carry is nearly limited by nothing but the optics at each end.
That doesn't solve the chicken and egg problem.
What probably would is something like having PCIe and USB to 1Gbps fiber adapters that cost $5.
You've been able to get Intel X520 NICs [0], with transceivers included for ~40USD on Newegg for a long time. This is a little more than double the price of Newegg's cheapest single-port 10/100/1000 copper card, but even the cheapest available such card is three times your "chicken and egg"-solving price point.
I suspect the combination of the absence of cheap-o all-in-one AP/router combo boxes with any SFP+ cages and fiber cabling's reputation of being extremely fragile have much more to do with its scarcity at the extremely low end of networking gear than anything else.
[0] This is a two-port SFP+ PCI Express card
In practice though 10G via copper requires pretty perfect terminations. The slightest error leads to crosstalk issues.
Ymmv. I've got a mix of cheap premade patch cables and some I crimped from solid core, all cat5e, all holding 10gbe totally happily. I suspect that only works because they're a meter or two long but that reaches across the rack.
Good thing the ranges for 25Gbase-T are short enough to make it impractical for home use.
Anyone who talks about 25GBASE-T like it actually exists, doesn't know anything about what they're talking about.
Or is speaking in future terms.
40Gbase-T will never exist, sure. 25Gbase-T very likely will.
Is the energy consumption inherent to 10Gbase-T? Or is it that 1Gbit nics have been around forever and optimised ad infinitum?
To be fair, the power consumption is also my biggest gripe with my WiFi 6 AP, they run extremely hot.
It's inherently worse than anything fibre, or even DAC cables (which are kinda cheating.) It needs a shitton of analog "magic" to work with the bandwidth limitations of copper cabling.
How easy can an ordinary home user install fiber in his home compared to a good old wire?
There’s nothing hard about it if you can run pre-terminated patches. Which you typically can since the connectors are so small.
So you're saying users could buy stuff like this? "25m (82ft) Fiber Patch Cable, 1 Fiber, SC APC Simplex to SC APC Simplex, Single Mode (OS2), Riser (OFNR), 2.0mm, Tight-Buffered, Yellow", https://www.fs.com/eu-en/products/282133.html?attribute=1031...
Heck, I don't even know what I should buy for 10G SFP+ ports and a distance of say 30 meters. Guess, I'm back to CAT6 :-)
Can these support local LLM’s?