I also managed to get my hands on an AMD Radeon RX 7900 XTX GPU and to get it working, using the same applications as before. Results:
- Geekbench - score here; note that the last workload failed verification, which is probably the reason for the really low score; otherwise, most of the time the values are 2-3 times lower than on x86 using the Vulkan API, which for some mysterious reason is not supported on AArch64
- GravityMark - OpenGL, Vulkan
- llama.cpp - see here
- Raymarching Primitives - essentially locked at 60 FPS, as expected
The software situation has improved tremendously since I tested the previous AMD card - the Ubuntu kernel developers seem to have backported the fixes to the amdgpu driver, so I am able to run the stock kernel version (e.g. 6.14.0-35-generic) and I no longer need to build my own (unless I want to 
). Also, I don’t experience any lock-ups anymore after disconnecting the HDMI cable, but I have to admit that there are some occasional issues such as crashes. On the other hand, subjectively they feel much rarer and they might be due to something that is not related to the GPU.
Unfortunately I still had to update the firmware on the Orion O6 board - even the version that could handle GeForce RTX 5080 seemed to get stuck in a PCIe device initialization loop, judging by the EDK II log coming out of UART2. In the end I settled on the following versions:
-
radxa-pkg/edk2-cix: e4f0fa10f2bbfde79105c82771a3963c75a14b97 -
radxa/edk2: 9744ad5917cd5496042b94ecdd30338087bd7ecb -
radxa/edk2-non-osi: 90dc2477c7119a8e30964e0f74ccc0230e67beb9 -
radxa/edk2-platforms: c755a07d8d5f80142fdbeea85aad767ceea256a7
Finally, several months ago when I first received the Orion O6 board, I tried it with an AMD/ATI Radeon HD 4650 card and everything seemed to work fine out of the box with the stock firmware, even though I didn’t test as extensively. I didn’t mention it before because that hardware is positively ancient, doesn’t support 4K display output, Vulkan, and so on - I bought it 16 years ago!