Realtek 10 GbE USB Adapters might be on the way?

[Patriot]

I can only report what i see, I will happily do some testing this weekend

Here is a thought, since USB4 gen2x2 is also 20Gbps maybe the firmware in my Diewu also implements this link mode besides the "normal" USB3 gen2x2

So long as it has 2 lanes it is fine.
My Zeph G16 has many USB4 ports, but only 1 is 40Gbps and guaranteed to have 2 lanes. The 20Gbps ports could be 1 or 2 lanes.
And the 10 is most certainly 1.

This is just a repeated headache brought on by USB-IF being absolutely terrible at their naming conventions as well as an architectural shift to thunderbolt. And requires extreme clarity in marketing material to avoid blowback from unexpected behavior and they are lining themselves up for it by advertising thunderbolt support when it is not a native thunderbolt device and requires 2 lanes to work at full speed.

They are trying to mitigate it by labeling 7Gbps as expected performance. We got 9Gbps in our lab but you can only expect 7... because windows and drivers. It is misleading even if the origin of the chaos isn't their fault.

 

[SlowmoDK]

my new MS-02 Ultra has 2 different thunderbolt/usb4 ports through 2 chips ... both those work with RTL8159 at full speed under linux with HWE Kernel

That you should be able to test yourself right away ... im away from "playground" atm

@Patriot

 

[Shonk]

From the documentation i have looked at the RTL8159 is not USB 4.0 in any real manner apart from being implemented by the USB controller in legacy mode and is USB 3.2 Gen 2 x 2 e.g. what Z690 and Z790 has

 

[Patriot]

my new MS-02 Ultra has 2 different thunderbolt/usb4 ports through 2 chips ... both those work with RTL8159 at full speed under linux with HWE Kernel

That you should be able to test yourself right away ... im away from "playground" atm

@Patriot

That is technically USB4 V2 on that box... so its good that it works at proper speeds lol.

 

[SlowmoDK]

That is technically USB4 V2 on that box... so its good that it works at proper speeds lol.

It has both USB4 v2 and USB4 v1, both are fine with RTL8159 at full speed

 

[trumee]

Will this work with framework 13 laptop AMD AI 300 series?

It has 4 usb-c ports and supports the following:

 

[SlowmoDK]

Will this work with framework 13 laptop AMD AI 300 series?

It has 4 usb-c ports and supports the following:

Yes all 4 ports are compatible with RTL8159 running at full speed

 

[Shonk]

Yes all 4 ports are compatible with RTL8159 running at full speed

No only the USB 4 ports are able to do USB 3.2 Gen2 x2
The other ports are USB 3.2 Gen2 ie 10Gbps before usb overheads so 6.7Gbps of throughput

 

[Shonk]

Not true

I have tested my RTL8159 on three different USB4/Thunderbolt ports, all 3 gave me the full 20Gbps aka 2 10Gbps lanes
2 ports based on Intel and one from AMD

So the marketing is actually not that misleading at all..

Does USB4 ports exists that doesn't support gen3x2 proberly yes, but it far from all that dosen't

I have looked into this further as i havnt really done a deepdive since Thunderbolt 5 came out

USB 3.2 Gen2x2
Intel Thunderbolt 3 Controllers = No
Intel Thunderbolt 4 Controllers = No (edit Metorlake embeded Thunderbolt 4 adds support back in)
Intel Thunderbolt 5 Controllers = Yes
ASMedia ASM4242 = Yes
Realtek RTS5490 = Yes

Since ASMedia make the PCH for AMD depending on the generation of IP ASMedia Used it may or may not do 3.2 Gen2x2 ie the newer it is the more likley it will be based on ASM4242 IP

Your MinisForum Device's USB 4.0 Ports are implemented with an Intel Thunderbolt 5 Controller but havnt been certified by MinisForum so they cannot call it Thunderbolt 5 so yes USB 3.2 Gen2x2 works fine on it

 

[ArusHear]

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

 

[SlowmoDK]

nyone 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

I also have no issues under windows with RTL8127AF, but when placed in MS-02 Ultra, It broke both onboard RTL8127 (RJ45 version) and RTL8127AF.
With both installed i was not able to get link on either..

A night of troubleshooting came up empty.. It seems support for SFP+ version is very limited under linux atm even with HWE Kernel/latest driver from Realtek



After testing all the various versions of RTL8127 and beyond ..

I ended up using my trusty X710-DA4 ... and all my troubles just vanished

 

[SlowmoDK]

@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

 

[Bulls729]

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

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 also have no issues under windows with RTL8127AF, but when placed in MS-02 Ultra, It broke both onboard RTL8127 (RJ45 version) and RTL8127AF.
With both installed i was not able to get link on either..

A night of troubleshooting came up empty.. It seems support for SFP+ version is very limited under linux atm even with HWE Kernel/latest driver from Realtek



After testing all the various versions of RTL8127 and beyond ..

I ended up using my trusty X710-DA4 ... and all my troubles just vanished

Sounds like it could be a platform-level problem rather than a driver issue. PCIe resource allocation, IRQ conflicts, or BIOS limitations are the usual suspects when two devices that work independently stop working when both are present.

Worth checking dmesg | grep -i r8 and lspci -vvv for both devices when they’re both installed to see if the kernel is even enumerating them properly. If one is getting starved for PCIe resources or there’s an IRQ conflict, the errors should show up there. Also check if the MS-02 Ultra BIOS has any settings related to PCIe lane allocation or bifurcation that might be relevant. Were you running the mainline r8169 or the out-of-tree r8127 driver when both cards were installed?

 

[SlowmoDK]

I'll revisit RLT8127 support in 6 month, but for now I've moved on

 

[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.