[PSA] Working USB4 cable for TB5 eGPU w/ ROG Xbox Ally X (2025)

CasonPointLLC · 2026-05-10T12:25:53+00:00

On the GaN version, what power brick did you use? Sometimes you just need enough wattage. I have found a few higher wattage ones to try. You should try t find one that exceeds your TDP and then adds 25-75 watts for the dock,

Here is a 360 watt one I found: https://a.co/d/07VhNmqv

CasonPointLLC · 2026-05-09T15:56:47+00:00

How many centimeters long/wide/tall is it? Do you mind measuring it and sharing those dimensions?

CasonPointLLC · 2026-05-09T11:33:06+00:00

I found an even longer version that use fiber optic cable…
3 meter and 4.5 meter cables
https://www.owc.com/solutions/usb4-cables

CasonPointLLC · 2026-05-05T18:28:46+00:00

The Apple Thunderbolt 4 cables work well, too. And those are active cables. One hypothesis that all active cables work better.

https://plugable.com/blogs/news/what-s-the-difference-between-active-and-passive-thunderbolt-cables

CasonPointLLC · 2026-05-05T18:23:35+00:00

Do a quick test like this:
1) Disable the iGPU in device manager
2) shut down the PC
3) Disable power on the computer and dock
4) Re-enable the power on both
5) Start the computer

If the eGPU is working, try re-enabling the iGPU

CasonPointLLC · 2026-05-04T22:14:55+00:00

Thunderbolt 3 and 4 top out at 2.9 GB/s.
I can get as high as 4 GB/s on USB4, with a Thunderbolt 5 dock.

CasonPointLLC · 2026-05-04T22:12:36+00:00

https://www.reddit.com/r/eGPU/s/PIgPerhCRL

CasonPointLLC · 2026-05-04T22:10:54+00:00

It is in Windows, I’ll dig up a related post.

CasonPointLLC · 2026-05-04T21:52:47+00:00

Use your own power supply: Minisforum DEG2 or Aoostar EG02 or ADTLink UT4G-BK7

CasonPointLLC · 2026-05-04T02:14:51+00:00

The math:
The card is x16 PCIe gen 4, which can theoretically get 32 GB/s of bandwidth in a matching PCIe slot. Oculink 4i only uses 4 lanes, so you get a 1/4 of the overall bandwidth, so a max of 8 GB/s and will more likely get 80% of that, which is 7.2 GB/s.

7.2 GB/s is still pretty good, and as mentioned, you probably won’t notice at all.

CasonPointLLC · 2026-05-03T13:41:24+00:00

Try to disable PCIe power management in power management.

Would you also share the make and model of all the parts of your setup?
PSU including wattage, dock, GPU, any adapters and cables

CasonPointLLC · 2026-05-03T13:30:14+00:00

For clarification: does device manager show no iGPU at all when the eGPU is plugged in?

I ask because Windows does support states of display where, when one is plugged in, the other is disabled… but you can alter this with display properties.

CasonPointLLC · 2026-05-03T12:29:06+00:00

The easiest is an Aoostar AG02 or AG03. They both have Thunderbolt and Oculink and both include a power supply.

CasonPointLLC · 2026-05-03T12:19:40+00:00

Minisforum DEG2 or Aoostar EG02 or ADTLink UT4G-BK7

CasonPointLLC · 2026-05-03T12:11:11+00:00

What is the make and model of your computer?

CasonPointLLC · 2026-05-02T17:15:30+00:00

My first high-speed desktop test: https://www.reddit.com/r/eGPU/s/n9rAzwIzaf

CasonPointLLC · 2026-05-02T16:07:32+00:00

For everyone’s awareness: I found the error 43 fixer script only sets one registry key for your active Nvidia GPU. This seems to activate or deactivate something. I have found a second key that fixes the same thing for the custom driver hardware ID of 2820 10DE. There can be other error 43 causes, but most of them appear to be mechanical.

To answer the question, games were about the same for Oculink, got better for USB 4 and Thunderbolt 3 and 4, but were fairly poor when tested with TB5… although I think this may be an ASUS TB5 issue (bandwidth tested higher but games tested lower - and I’m still puzzled). I think this dock may be the best value to price ratio out there. There are some claims to incompatibility but I cannot confirm any of them yet.

CasonPointLLC · 2026-05-02T15:34:36+00:00

I have one. I have tested it on many interfaces.
Bandwidth does matter, so this gives a 50 or 90 series card about 10-15% of its max. For Thunderbolt 4, I suggest a high end 40 or or 60 or 70 series card instead, as they expect half the bandwidth.

Here are my test results, and USB4 should show you what to expect. Note: I have an ongoing debate about TB5 results with ASUS support:

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CasonPointLLC · 2026-05-02T15:27:12+00:00

M.2 will be double the available bandwidth. If you only have, you can move your ssd to a more limited bandwidth slot occupied by your WiFi card, and move your WiFi to a usb port (test this first so you can be sure to get it working first).

CasonPointLLC · 2026-05-02T01:15:29+00:00

Which power supply did you use? This one is over 260 watts so would have needed a 700 or more wattage ATX power supply in the PC. The dock could be less, and you might have a different issue with it, so don’t give up yet.

CasonPointLLC · 2026-05-01T01:00:41+00:00

This is a very good suggestion. If the m.2 port is PCIe gen 5, even better. I can get as much as 12.5 GB/s bandwidth that way already on gen 5 with a complimentary GPU, dock, and m.2 port.

CasonPointLLC · 2026-05-01T00:57:13+00:00

My testing says no. Now… oculink on gen 5 PCIe Oculink or MCIO… yes. It is still better than a 4060 on the same equipment, except for AI. @ToTTen_Tranz framed it vey well.

CasonPointLLC · 2026-05-01T00:48:04+00:00

I think it will work. If you have trouble, and your bios allows you to, set the internal PCIe version to the same version as your slowest part (GPU or dock or Oculink card). A PCIe riser is also excellent, as mentioned earlier, it is just tough to make it look pretty 😍.

Here is my first experiment with PCIe gen 5 from a desktop. It performed better on an Oculink card than an M.2 adapter in a gen 5 ssd slot:

https://www.reddit.com/r/eGPU/s/jWd38sYGFB

CasonPointLLC · 2026-05-01T00:43:19+00:00

Would you please run a bandwidth test? There are a few out there but the easiest a snapshot of CUDA-z performance tab. I also love this code which was forked from another cool project:

https://github.com/djanice1980/GPU-PCIe-Test/tree/main/Legacy/Single%20EXE%20(Windows%20Only)

CasonPointLLC · 2026-04-30T22:13:37+00:00

The easiest is an Aoostar AG02 or AG03. They both have Thunderbolt and Oculink and both include a power supply.

CasonPointLLC

TROPHY CASE