Realtek 10 GbE USB Adapters might be on the way?

[Shonk]

@Shonk

On the MS-02 I have both a USB4 v2 controller
82:00.0 PCI bridge: Intel Corporation Thunderbolt 80/120G Bridge [Barlow Ridge Host 80G 2023] (rev 84)

And a USB4 v1
00:0d.0 USB controller: Intel Corporation Meteor Lake-P Thunderbolt 4 USB Controller (rev 10)

Both support 20Gbps

So

Intel Thunderbolt 4 Controllers = No

is not true for all im my testing

But in fairness a very new implementation of T4

for the longest time Thunderbolt didnt include USB 3.2 Gen2x2 at all

If your buy an external Thunderbolt 4 Card it doesnt support it unless they have released a new revision without any fanfare
They have realised this omission and added support back in on Thunderbolt 5 and it seems also on newer Thunderbolt 4 thats embeded on mobile devices

 

[SlowmoDK]

If your buy an external Thunderbolt 4 Card it doesnt support it unless they have released a new revision without any fanfare
They have realised this omission and added support back in on Thunderbolt 5 and it seems also on newer Thunderbolt 4 thats embeded on mobile devices

Ya and if this has been your trial and error for years, I can see why bad wording in some adverts would grind teeth

My AMD 7735HS Beelink proberly has that ASMedia combo you mentioned, because I also get 20Gbps on that USB4 port

These are my first thunderbolt/USB4 devices and to me that listing didn't say anything that struck me as "very" misleading, because I got 20Gbps on all the ports hehe

Hopefully we can move past that

 

[Shonk]

Ya and if this has been your trial and error for years, I can see why bad wording in some adverts would grind teeth

My AMD based 7735HS based Beelink proberly has that ASMedia combo you mentioned, because I also get 20Gbps on that USB4 port

These are my first thunderbolt/USB4 devices and to me that listing didn't say anything that struck me as "very" misleading, because I got 20Gbps on all the ports hehe

Hopefully we can move past that

Its a good thing that support seem to have been finally added back in
but its apparently still oem dependent as some oem's if they skimp can still mess it up

My devices with Thunderbolt 4 dont support it at all via Thunderbolt

i9-11950H
i9-13900H Doesnt support it on Thunderbolt 4 but does have a native USB 3.2 Gen2x2 port

 

[ArusHear]

There’s an open report on the Linux netdev mailing list from November 2025 that describes what looks like the same issue: RTL8127AF detected fine, no link over SFP+ DAC.

netdev: RTL8127AF doesn’t get a link over SFP+ DAC

In that case, the problem was the mainline r8169 driver, which doesn’t properly handle SFP+ link negotiation on the 8127AF. It reports the port as “Twisted Pair” even on the SFP+ variant and can’t disable auto-negotiation. The reporter resolved it by switching to the out-of-tree r8127 driver from Realtek, which brought link up immediately at 10G full duplex.

Now, you mention you’re already running the r8127 11.016.00 driver from Realtek’s site, so the obvious fix doesn’t apply here. A few things worth checking though:

First, verify the out-of-tree driver is actually the one bound to the device. Run ethtool -i <interface> and confirm it shows driver: r8127 and version: 11.016.00. On Proxmox, the mainline r8169 can race the out-of-tree module at boot and grab the device first, especially if r8169 wasn’t explicitly blacklisted. If you see driver: r8169 in that output, the Realtek driver compiled fine but never got to claim the card. Blacklisting r8169 in /etc/modprobe.d/ and rebuilding initramfs (update-initramfs -u) would be the fix there.

If it is confirmed r8127 and still no link, check what dmesg | grep r8127 shows. The netdev reporter’s Realtek driver output showed “Supports auto-negotiation: No” on the SFP+ interface, meaning the DAC connections are forced rather than negotiated. In their case link came up automatically. If your dmesg shows the driver loading but no “link up” message, try forcing it with ethtool -s <interface> speed 10000 duplex full autoneg off on the r8127 driver and see if that changes anything.

Also worth posting the output of ethtool <interface> with the r8127 driver loaded. Specifically what it shows for supported link modes, port type, and auto-negotiation. If it’s still reporting “Twisted Pair” and “Auto-negotiation: on” with the Realtek driver, something may not have compiled or loaded correctly.

I saw this link/e-mail conversation in this thread page 7 or 8.
I tested with r8169, after PVE upgrade - no option for fiber only for ETH.

And r8127 with all option set using ethtool make clean build etc, Realtek driver sh automatic blacklist r8169.

With combination, and static set autoneg off and full duplex etc i have link for 0.5 sec and link down..
Realtek can make good driver for Windows and very bad for Linux - I don't understand this..

 

[Karpenko Yuri]

Hi,

anyone have working RTL8127AF with SFP+ DAC passive or active AOC have link on linux?? I try everything with no succes..still no link :c
With Windows work good with setup in driver settings 10G Full Duplex

My setup:
RTL8127AF XikeStor SKN-8127AF-1SFP+ aliexpress.com/item/1005011607908697.html
Proxmox 9.1.6 6.17.13-1-pve

Cable:
10G SFP+ DAC (3 diffrent)
10G SFP+ AOC


Drivers: 11.016.00 from Realtek website

Switches for TP-Link Omada:
SG2210XMP-M2 v1.0
SX3008F v1.20

Hi!

I have absolutely same config.
Driver 11.015.00 - link ok.
Driver 11.016.00 - no link.

 

[gxcreator]

Disassembly of DIEWU USB-C 10gbe Ethernet Adapter based on RTL8159 I've got from Aliexpress.

 

[gxcreator]

PCIE 4.0x1 vs PCIE 3.0x4 (actually x2) RTL8127 boards comparasion

 

[boerni666]

I saw this link/e-mail conversation in this thread page 7 or 8.
I tested with r8169, after PVE upgrade - no option for fiber only for ETH.

And r8127 with all option set using ethtool make clean build etc, Realtek driver sh automatic blacklist r8169.

Ran into the same Problem: r8127 PCIe 3.0 x2 SFP Card not working with DAC OR any transceiver.


But the problem is fixed in linux 7.0...which isn't released yet. Had to download and compile the 7.0rc6 Kernel. Now the System runs fine and stable so far. Card works great.

 

[WhiteNoise]

It seems that the Cable Matters 10G USB adapter is substantially lighter than the other models (like 50grams vs 120grams). Does it get **too** hot at 10G?

 

[boerni666]

Source for Linux 7.0 starting to support the R8127 SFP+ card: Linux 7.0 Networking: Prepping For WiFi 8 UHR While Dropping Last Parallel Port Ethernet Driver - Phoronix

 

[jmsq]

Looks like WisdPi has finally launched a variant as well: USB 3.2 10Gb Ethernet Adapter RTL8159

 

[Shonk]

With regard to firmware on the PCIe cards i have 7 cards of different variants of the RTL8127

DIEWU RTL8127 Firmware 2.073
LEKUO RTL8127 Firmware 2.074
DIEWU RTL8127AT Firmware 2.073
DIEWU RTL8127ATF x 2 Firmware 2.075
LEKUO RTL8127ATF x 2 Firmware 2.077

I dumped the SPI of all of my cards

Anyway the firmware has nothing specific to the card in it e.g. the MAC or anything
and is fully interchangable from any model

The DIEWU cards can be read and written to just fine with a CH341 in situ
The LEKUO cards cannot (if you fit a 1.8v module you can read the SPI in situ but cannot erase them or write)

Long story cut short LEKUO block access to the SPI in a powered on state that the 1.8v module seems to bypass for reading
I presume by being enough to bring the SPI up but not enough power for the card and certainly not enough power to write to the SPI
I ended up issuing an erase command on the LEKUO 2.074 firmware at 3.3v when it failed to detect and on fitting the 1.8v module i could see that it had been erased so replaced the SPI (FENTECH 25VQ40CTIGT) with a PUYA chip that i have about 40 of that i know are not problematic

I wrote the 2.077 firmware to it before fitting

Just fitted and still has flux all over it before cleaning with isopropanol..


Anyway they all run Firmware 2.077 now
and the PUYA acts like the FENTECH SPI did in situ now and can only be read with the 1.8v module and such
so its some sort of protection for sure that the LEKUO cards are doing

Luckily i only had to pull the chip on one card as the other LEKUO cards where already on 2.077

I have these backed up if anyone ever needs one


Here's a few images of cards that have been updated
I tested all the cards in an old Z390 M Gaming i7-8700K hence the different bios versions
Device Name: <null string> is normal for 8127ATF cards Realtek havnt got around to putting a name string for 8127ATF's yet in the UEFI option rom

 

[jmsq]

Has anyone noticed any difference in PXE support between the firmwares/variants of the RTL8159 devices? It's been a while but I couldn't get PXE working with the Diewu variants, granted I'm not sure it was a fault of the device/firmware itself.

In other news, RTL8159 (USB) support should be landing for Linux mainline in 7.2 Linux 7.2 To Support Realtek RTL8159 10GbE USB Ethernet - Phoronix

 

[Tinkerer]

...

Which of these would you recommend of these cards, if any?

Were you able to test WoL and PXE?
Were you able to test heavy loads?

Previously I've been testing 5Gbps USB adapters with Realtek chips. I don't know if it were drivers or a combination with the device but I couldn't get those to be stable.

iperf3 -c 1.2.3.4 --bidir -P 4 -t 300

This will start 4 streams, bidirectionally and test for 300 seconds (5 minutes). If you want to rule out a switch or other device, connect them directly and set fixed IP's or something.

My previous tests would crash the kernel module, sometimes within seconds. I had purchased 6 of them and I worked with Wavlink support extensively. They provided new drivers to test, different parameters and even send me a new device to test for them. I ended up sending all 7 back for a refund because we couldn't get them to work stable.

Some devices actually worked quite well as long as I didn't push them. I remember one of them wouldn't crash until I tested bidirectionally.

I even tried cooling them with an external fan (casing is aluminium so that worked quite well too).

All my testing was done from several different PC's, all Archlinux.

It would be great if you're able to test these cards

Thanks!

 

[Shonk]

WOL works fine on RTL8127 and RTL8127AT
e.g. RJ45 Versions

From S3 or Powerered off state

WOL on RTL8127ATF (SFP+ Card) the uefi doesnt seem to register the WOL packet from a cold off state
e.g. power pulled and pc not powered up at all, the link is active just the uefi doesnt power the pc up

if you power on the pc then shut it down manually WOL is fine then from then onwards until you pull power again

I have bypassed this issue by having the uefi last power on state to on rather than memory
e.g. if the power is pulled next time power is restored the pc will boot S3 is then fine

Some older pc's i find setting PCH aspm to off or manually disabling Power Management in the Nic
seems to solve any nic driver crashing issues

e.g. Z790 Aorus Pro X i can leave aspm and power management on fine
Z390 Aorus Master, Z390 M Gaming i disable power management on the nic, i think its down to 8127 Driver Maturity
and them being overly optimistic with power saving features on platforms they havnt tested fully

and i can fix it with either turning off PCH ASPM or just going into the nic and manually disabling Power management on that nic

Someone had a switch crashing issue the other week and wanted to know if my switch was resetting
anyway i left iperf running for about 10 hours 9.91Gbps of payload (9k Frames) had no issues at all

So yeah they seem stable

Brand wise the Diewu cards seem a slightly better BOM but the pcb is a bit bigger
both brands are seem fine though the Diewu cards have the larger heatsink for sure

If you dont care about its size get a Diewu

 

[Tinkerer]

Someone had a switch crashing issue the other week and wanted to know if my switch was resetting
anyway i left iperf running for about 10 hours 9.91Gbps of payload (9k Frames) had no issues at all

Was this bidirectional or one-way, either up or down?

Thanks for the elaborate answer!

 

[Shonk]

Was this bidirectional or one-way, either up or down?

Thanks for the elaborate answer!

It was this

iperf3 -t 6000 -c 192.168.0.2 -R
iperf3 -t 6000 -c 192.168.0.2
pause

Like so

 

[Tinkerer]

I see you tested both ways, but not simultaneously.

iperf3 -c 1.2.3.4 --bidir -P 4 -t 300

Does both up and down simultaneously. It a little harder on the card and drivers handling all buffers and offloading both ways. Some of the USB devices I tested previously worked fine one way but crashed with --bidir parameter.

perhaps for next time .

Cheers!

 

[Shonk]

the server is doing a windows update atm once its finished i will run it for you gime 10mins

 

[Shonk]

Here you go

9900K to 12900k
one was Diewu ATF other was Lueko ATF






Plugged into a Xikestor SKS8300-12X that im in the middle of migrating to from An 8 Port RTL9303