This is very very helpful. Thank you
Would you mind sharing the riser cable you are using and whether it’s externally powered?
Thank you!
I didn’t use a direct riser cable, but a powered adapter board connected to a x4 pcie adapter using slimsas cable.
Basiacally these:
Some amazon links (not the exact ones I have, but they are mostly generic passive boards):
I already had the adapter boards, so I just needed a cable to connect them.
Could maybe also do it with mcio based boards, but I haven’t seen many of the mcio 4i cables and pcie adapter type boards that would fit in the framework desktop x4 slot.
Reporting back with my findings.
I installed a Reaper 9070 XT on the x4 port using a K23SL-TL riser. Using a 15cm for now, but need a 25cm for my fractal terra.
BIOS version 3.05, although I saw no difference in behavior in 3.04
At first, I tried using the riser without external power, and everything “appeared” to be working. LACT shows negotiation at pcie 4.0 x4 speeds, the 9070 XT, got good FPS in games, benchmarks lined up to expectations and I saw the power draw from the 9070XT to 340W no problem. This is on cachyos.
I then tested on windows and also got good results, except at some point there was a driver conflict. I booted back up without the 9070XT, ran DDU, rebooted with the 9070 XT and reinstalled the drivers from AMDs website and everything has been fine since. Got Steel Nomad scores slightly below average but that is expected with the pcie bottleneck.
I then attached a molex 12V connector to my riser so I could compare the differences. While everything “appeared” to be fine without external power, attaching the power cable boosted my FPS and power draw of the card, so I think it’s necessary for optimal performance.
Now the issues:
I didn’t have any boot issues or need any kernel flags (pcie power mgmt was already disabled windows), but when my two monitors were plugged into the dGPU, I could not come back from suspend in Linux. The machine would wake and i could SSH, but no video. At suspend, the dGPU fans would ramp up for a minute or two. Reloading the GPU through a script seems to fix it, but my whole session would be restarted so it was not ideal. I then tried plugging in one of my monitors to the igpu and the suspend issue from the dGPU side went way, but then the CPU cooler fan would ramp up and stay ramped up when entering suspend. I tried a bunch of different kernel flags:
amdgpu.bapm=0 amdgpu.aspm=0 pm_async=0 amdgpu.sg_display=0 amdgpu.runpm=0 pcie_port_pm=off
None of them seemed to work, but I still have them applied and have not gone through pruning. At this point I gave up and since I was having USB suspend issues on BIOS 3.05 anyway, I am just going to continue with suspend disabled. Windows has no such issues.
I had similar experience and landed on the same decision to not use suspend under linux. Most of my usage under linux is just running LLMs and accessing the system over the network and then shutdown or reboot to windows for certain games.
For example I ran into the fan spinning even in idle for my R9700 after some LLM use:
There are other RDNA4 linux fixes coming in 7.0+.
For the most part it has been pretty stable, but I do get occasional issues with RDNA4 dgpu display output not working on boot. It seems to be transient and may not be specific to just being hooked up to the framework desktop.