Posted by Alupis 1 day ago
USB 3.2 Gen 2x2 is the very rarely supported 20Gb/s variant of USB 3, and making devices now that require that for full performance is a weird decision, with high-speed capable ports generally having wider support for either USB4 or Thunderbolt3+. I imagine the reason would be that some chip with an otherwise poor market fit got cheap...
Throwing this into the mix definitely doesn't improve the USB-C "what does this port support" conundrum, but this specific one predates USB-C and is not at all something you'd normally hit.
3.2 Gen 2x2 (and the occasionally relevant 1x2 if you have a weak cable) are USB C only.
USB C ports and cables have 4 USB 3 "superspeed" lanes rather than two. When you use an A to C cable only one pair of those connects. The point of the "x2" modes is that they use the second pair of lanes that would otherwise go unused.
Except of course they don't always go unused. DisplayPort Alternate Mode sends DisplayPort over those two "unused" lanes getting you USB 3 data alongside a half speed DisplayPort connection. (or alternatively full speed DisplayPort on all four and only USB 2), and then of course Thunderbolt 3 and modern USB4/TBT4 use all four lanes and tunnel everything.
Thank you for answering a question I didn't know I had
However, I'd hold that this is an extension of the USB 3 mess that predates USB-C, even if the x2 mode specifically was a USB-C addition.
The important thing for people to know is that support for USB 3.2 Gen 2x2 is practically non-existent: TB3 came before as a well-established (but premium) solution, and USB4 just two years after to commoditize it. A complicated solution with mid-tier bandwidth and none of the flexibility didn't attract attention, so support is poor.
The main application of 20 Gb/s USB ports is to connect external NVMe SSDs, when faster USB 4 or Thunderbolt ports and SSDs are not available.
For an external NVMe SSD on USB, a 20 Gb/s USB port will double the throughput, unlike for a 10 Gb/s Ethernet interface where any improvements are completely negligible.
I do not think that 20 Gb/s USB Type C ports are "very rarely supported". Every mini-PC or desktop motherboard that I have bought during the last 10 years had at least one such USB port.
Such ports appear to be rare only on laptops, because most laptops have very few USB ports.
While this may be theoretically (almost) possible, I’m quite sure this is absolutely not the case in practice.
For example see these benchmarks of one of the more recent USB to Ethernet chipsets [1], that can reach ~9.5 Gb/s on USB 3.2 Gen 2x2 but only between ~6.2 to ~7.3 on 3.2 Gen 2x1 laptops.
1. https://www.jeffgeerling.com/blog/2026/new-10-gbe-usb-adapte...
Edit: Haha, didn’t realise TFA was by the same author as these benchmarks but he’s done a lot of testing and benchmarking of these kind of devices over a long time, and it agrees with all the other benchmarking from other people I’ve seen too!
In USB 3.2 Gen 2x1, the actual USB packet throughput is 9.697 Gbps and the "10 Gbps" refers to the raw encoding rate.
This difference means you are guaranteed to lose at least a few hundred Mbps off maximum performance. It's not really a practical concern, but it's not an error to say 10 Gb/s USB ports lack the bandwidth needed to support the maximum performance of a 10 Gbps USB Ethernet adapter.
Are you talking about USB 3.2 Gen 2x2 though? Because I've never seen any MiniPC with this port and as for motherboards, I checked my local retailer and only ~15% of currently sold ones have Gen 2x2 (mostly high-end ones).
With mini-PCs, I frequently use external SSDs, so I certainly used those ports at their full speed.
The only mini-PCs that I had in recent years without such a fast USB port were Arm-CPU based, as those are typically starved in fast peripheral interfaces in comparison with the Intel/AMD CPUs.
> The main problem is USB-C's bandwidth complexity - especially when paired with the Realtek RTL8159 Ethernet controller, which requires USB 3.2 Gen 2x2 (20 Gbps) to get the full rated 10 Gbps speeds
Jeff's statement wasn't that 10 Gb/s Ethernet requires 2x2. It's that that requirement comes from a very specific controller.
The first half is true, the second half is not. Remember overhead. You don't need 20GB/sec, but you need to take into account the USB overhead.
I am of the opinion that 5Gbe is a much more sensible speed for a laptop adapter right now as it uses half the power and can obviously run full wack on 10Gb/s USB so you're looking at like 5Gbe vs ~9.4Gbe.
At distances where Cat.6A is even an option the demands on the fiber are very low. And it uses less power than the BASE-T PHY. The cable at least without integrated power is very thin as well, unless you can't respect it enough to not kink it, in which case you'd want a thicker one just to prevent you from being able to break the fiber.
And you get much better future proofing with SMF. And if you do need a long fast run, SMF is what you want.
How do I power an access point with fiber? Ok we add an AC wall socket to the ceiling but now we need a 'brick' to convert to DC. How do I remotely hard reboot an access point if it were to crash?
Fiber termination requires a fusion splicer and a trained engineer, sharps box etc. The power socket needs an electrician. It's just such a nightmare in comparison, install is going to be more expensive, longer to fix faults, less flexible to move a socket etc
So the their maximum speed is approximately 9.7 Gb/s.
Then for Ethernet there is a protocol-dependent overhead, e.c. depending on whether TCP or UDP is used, and depending on whether standard packets or jumbo packets are used.
The TCP overhead can reach in the worst case up to close to another 3%, reducing the achievable TCP throughput to around 9.4 Gb/s.
The USB frames add some extra overhead, but it is normally not important in comparison with other factors that can reduce the throughput.
All that a 20 Gb/s USB port can do is to reduce the overhead of the USB frames, but that is a negligible improvement. Using jumbo Ethernet frames (which are 6 times bigger than standard frames), if both ends support them, is likely more useful for increasing the throughput, than using a 20 Gb/s USB port.
That's probably the missing cherry on top, as having vpro once the framework motherboard gets reused as a home server it gives some manageability features.
An Intel WLAN card in an M.2 slot on the mainboard might work (given your givens; a vPro enabled chipset).
i see, i did not know about this.
however, let me use your knowledge and ask you another question: vpro-enabled thinkpads without an ethernet port do have a dongle that should allow vpro-usage.
is that some kind of vpro-specific dongle? i mean, iirc that dongle also has to be connected to a very specific port
I appreciate the USB-C nature of the Framework's expansion ports, it does make real the entire reason that USB was created in the first place, hot plug slots. Still, I (and others) pointed out to Intel early on that using Ethernet with a specific packet type would be cheaper and just as fast (which the ATA over Ethernet folks proved), but then you wouldn't get the 'certification tax' that the USB consortium extracts. :-).
Cynicism aside, the design issues suggest that it might make sense in future laptops to have heat spreaders around the plug in port, although that makes things thicker and people obsess over thinness.
What difference does a docking station make? Sometimes you want to spend a minute or two setting up your laptop in a more serious way, and that's just as reasonable with or without a docking station.
I've put a disproportionate number of hours and $$$ into my homelab over the years, and I still only have 2.5G Ethernet switches deployed. Most offices' (much less home/coworking space/etc.) network traffic is passing through single-gigabit switches.
That said, I'm kind of sad that Framework and others have generally opted to let "third party USB-C docks" be the docking solution. I miss the days when my Thinkpad dropped onto its docking station with a purpose build bottom connector and seamlessly became a desktop/deskside type computer that was wired into my desk setup. Sadly I think that vision of docking died with the Thinkpad's sale to Lenovo.
For $20 you can get something that will pass through power from a USB-C charger, 4k HDMI to a monitor, and provide gigabit ethernet and some USB ports. We're no longer in the bad old days of USB 2 where USB ethernet was noticeably slower - or of $$$ vendor-specific, laptop-specific docking stations.
And if you don't have a dedicated desk where you can set up your docking station, you're probably not going to enjoy the wired ethernet experience, because without a desk you'll have to crawl around to plug your ethernet cable into a floor port every time you move desks.
I still have a soft spot for laptops with built in ethernet ports, though, for connecting to devices in the field.
Back in the early days of wireless networking I had my laptop configured with the wireless and wired networks bonded. I want to say that was 2Mbps on the wireless, so if I was doing a big transfer I could walk over to a wired port in my house and plug in to get 100Mbps.
Unfortunately, all 3 USB-C dongles I tried had significantly worse performance than the built-in 1 gig ethernet on the dock, apparently using the RTL8156 chipset which is known to be unstable.
I've got a 4th dongle on the way to try next! If I buy enough of these things I'll have spent more than just buying the right dock in the first place.
https://frame.work/pl/en/products/dual-m-2-adapter
People have been making custom OCuLink adapters and recently Framework developed its own:
Try to load any modern website on dial-up. The connection will likely timeout before a full page load.
Once 5g became pervasive and data cheap, no one gaf about a cold load weight fitting on a floppy.
I’m still clutching my iphone mini, which after ios 26 just boggs down under the absurd weight of many pages and turns in to a space heater before reloading entire page b/c of error. No need for forced obsolescence when the enshittification of basic websites takes care of that for you. :-/
Expecting it to work full time in a laptop is a bit of a stretch of the heat dissipation budget.
Also, the laptop he is working has the AMD FP8 chipset - depending on how the ports are setup, he might only get 10G USB, if the ports are allocated to video instead.
These realtek 10gbe chips are more in the range of the Pi Zero class machines (0.5W idle, 2W loaded) which don't often come with heatsinks though they might benefit from them. If it has a good thermal connection to a good thick ground plane on the PCB, that's worth almost as much as a passive heatsink on the top of the chip.
usb-c < card edge < motherboard integrated in terms of how much heat can be transfered through the connection. Where the motherboard would have the largest ground plane to soak up heat from such an IC and dissipate it passively. The usb-c module is worst case by being a small enclosed box with very little thermal connection through the plastic insulating housing. An aluminum enclosure might dissipate enough heat passively to make it pleasant to use.
Even with a heatsink and fan, I had to upgrade to a higher quality set to keep Jellyfin from thermal throttling a Pi5 while transcoding 4K video.
(Technically the Pi 4's hw encoder doesn't go up to 4K either, though, so I guess moot point).
Another way is that my great grandchildren won't care about inheriting my collection of hobbyist SBCs, and therefore nor should I.
Subsequently, in 1967, Black of Motorola experimentally derived a median time to failure (MTTF, i.e., operational lifetime) model for EM in Al interconnects, showing that the time to failure due to EM is inversely proportional to both the current density and the absolute temperature of the interconnect.
[1]: https://infinitalab.com/blog/ic-failure-analysis-defect-type...
[2]: https://resources.system-analysis.cadence.com/blog/msa2020-b...
[3]: https://www.mdpi.com/2079-9292/14/15/3151#sec3-electronics-1...
* https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair#Var...
I'm having second thoughts about having one of those dongles on my desk all day for the same reason wireless charging seems wasteful.
Yes, except that most devices use Ethernet. So, at the end of the day, you still need Ethernet cables unless you want to deal with an additional switch or converter in every room.
Unless we're defining some networking standard, "Ethernet cable" is a perfectly acceptable term. Everyone will understand what is meant. The added specificity you're asking for doesn't improve the quality of communication.
And particularly for 10GE the heat and power problems are due to the copper transceiver DSPs.
And people nerdy enough to run 10GE at home might well run fibre.
So, no, the specifity is needed and useful.
You're still talking about a cable. The cable may be compatible with those standards, but you can put anything through it. It's just a physical connection.
>And people nerdy enough to run 10GE at home might well run fibre. So, no, the specifity is needed and useful.
No, because if you say "which do you want? Ethernet or fiber?" no one will look at you like if you asked if they want salt or beef. It's technically incorrect, but everyone will understand what is being asked.
If you want to ackshually, the post I was replying to was talking about what "devices use" and cables required for that, so it's in fact about what standards these devices support.
Apart from that, again, in the context of 10GE you can by no means assume copper when talking about an Ethernet port; SFP+ slots are quite common. Your assertion that "everyone will understand" is also something I plainly know to be untrue in my bubble. It may be true in the context of slower speeds, but for ≥10GE the general performance characteristics of twisted-pair copper transceivers are so bad as to make it into the crossover point from copper cabling into DAC cables and fibre.
And, honestly, the assumption that "Ethernet = copper cabling" is harmful for 10GE. Those transceivers are hot garbage in the literal sense, they run hot enough to warrant usage limitations on switches due to cooling/overheating limits, and they tend to be quite picky about cable quality on establishing links.
Yes, that person said "most devices use Ethernet", to which you correctly pointed out they meant to say RJ45. However, in the process of making that correction you made an unrelated error yourself in saying that fiber is Ethernet too.
>you can by no means assume copper when talking about an Ethernet port
You can, if by "Ethernet" you mean an RJ45 jack and its cable, which is a fairly common usage of the word. It doesn't matter that it's technically incorrect. The default idea of physical protocol that the word "Ethernet" invokes in most people is that of twisted pair copper cabling. If you take a random person and put in front of them a fiber optic cable carrying Ethernet and a copper cable carrying serial signals and tell them "would you mind unplugging the Ethernet cable?" they'll disconnect the copper cable.
>Your assertion that "everyone will understand" is also something I plainly know to be untrue in my bubble.
Oh, so you know several people who when presented with the dichotomy of Ethernet or fiber (because that's what the comment you replied to was about, as it put Ethernet in contrast with fiber), they'll be completely dumbfounded about what is meant, as if hearing gobbledygook?
Yes.
And I've used up the time I'm willing to sink into this subthread, see you around.
I disagree with that for two reasons. First, my central switch is probably capable of both copper and fiber. Second, how many wired devices do you have spread around your house? Let's say I have an above average number of devices: a router, a NAS, two access points, and three desktops. Router, NAS, and one access point can all be adjacent to the switch and avoid any conversion hassle. The desktops are using fiber so no conversion hassle there. That leaves one copper cable or converter needed for the other access point.
My house has a POE doorbell, several POE cameras, 2 TVs that each get a connection to their attached android TV boxes, Wife's office gets a pair of connections, ditto with mine, then you've got the APs for the wireless bits + a few servers in the rack with the networking equipment.
Mind you I know I am on the high side, but I use that as the reference point. I'd figure a normal house would have 4-5 wired connections to my 20ish.
That mainly leaves the TVs, which I would just throw on the wireless but for wiring I'd still say you run it to your central switching spot that handles both copper and fiber.
If you have a laptop or TV it probably doesn't need 10G.
It's hard to justify when Ethernet is catching up. Most new motherboards have a 2.5G port. High-end motherboards have 10G Ethernet ports. SFP cards take space, are ugly, and need directed airflow to stay cool. They are not worth it for a 4x increase in bandwidth at best.
I see how sloppy some FTTH installs are and they all work fine, and this is for light that travels for long distances.
The only advantage copper has is PoE.
I mean sure, I could install a sfp+ card, but the cat5 installed in 2003 or so works fine with my 10gbase-T equipment (maybe it won't work on all my runs, but so far I'm two for two and I ran out of 10g ports on my core switch). Why would I tear up my walls to run fiber when I have cabling that works for me. (I use dac for servers near the switches)
I have seen some attractively priced 40g equipment on ebay, but honestly 1G wasn't really limiting me, I just wanted to see if 10g would work.
I have seen the same with just usb-c multi-port dongles for macbooks (the ones they give you at work along with the macbooks).
in fairness to the docs/dongles though, they have an incredible amount of features that would have been science-fiction twenty years ago.
The same is true for 10 Gb/s Ethernet, whose speed is not exactly 10 Gb/s, but the difference from 10 Gb/s is also negligible.
Therefore, you do not need a 20 Gb/s USB to reach the maximum speed with a 10 Gb/s Ethernet interface, a 10 Gb/s USB port is good enough.
The overhead of data framing on USB is slightly higher than on Ethernet, so the maximum throughput on an USB 10 Gb/s Ethernet interface is a little lower than for a PCIe Ethernet NIC, but the difference is small enough to not matter. Usually other factors, like bad device drivers or inefficient programs, can cause much greater variations in Ethernet throughput.
The 9.4 Gb/s throughput obtained in TFA is perfectly reasonable when taking into account the packet overheads, which make impossible to reach 10 Gb/s for user data, regardless of hardware. A 20 Gb/s USB interface could not provide any serious improvement over that.
If I'm on the go, I'll have to take it out of the chassis while it's in my bag so I don't damage it. In that case, it's easier to have a regular USB-C card in that port, and toss a dongle in my bag instead of the expansion card.
If I'm not on the go, I'm at a desk, and I'd still rather plug in a dongle than regularly swap an expansion card.
I'm not saying you'd never want the expansion card, but it feels pretty niche.
While a regular usb-c ethernet adapter has a flexible cable between the laptop and the bulky rigid part.
The current crop has been great for my needs — a couple models have 10G Ethernet built in (CalDigit is the one I'm using now), and most now have more than one Thunderbolt port that allows a high speed storage device to be used as well (in addition to a 5K or 4K display or two!).
Anyway it is probably just there to demonstrate the possibilities to consumers. What if a lower profile standard for networking gets popularized?
I'm 1000% for wired connections where possible, but for laptops too thin to have one built inside of the frame the best choice is a proper docking station, ideally with a cable that isn't impossible to user replace.
The economics/upgrade math just does not make sense.
My best guess for Apple's actions is that despite there being a very real demand for a smaller phone, they don't think the discomfort is bad enough for people to switch to Android, so they don't even try. A small phone makes a lot of profit, but ignoring the demand also makes a lot of profit.
The Air was a real flop.
If it had a hinged or expanding[0] ethernet port so it could sit flush with the chassis when not in use it would make a lot more sense.
[0] It's easier to show what I mean https://www.reddit.com/r/TechnologyPorn/comments/hvlxep/orig...
No, you wouldn't. You'd have one of these instead: https://frame.work/products/usb-c-expansion-card?v=FRACCQ000... (or the one matching a color you prefer and your particular model)
Unless you're crazy and leave the expansion ports unpopulated.
A wider bag doesn't solve it. The part that sticks out could still easily snag on something. I wouldn't want to take that risk, and I doubt many people would.
I feel like you're arguing just to argue...