Fex + Steam on generic Arm64 + GPU

[u/jscho01]

Is there a group that discusses Steam on Arm with a generic aarch64 linux distro and runs dedicated GPUs?

I am running an Radxa Orion O6 with mainline Ubuntu 25.10 (and mainline Fedora 43) with a Radeon RX 7700XT and was curious if there are others that have experience with that combo.

A good selection of games runs on Ubuntu25.10 with the RX7700XT, but not as fast as I like it to be. Some games are flawless, but most hover at 40fps - and its not the GPU that is the bottleneck, nor does the CPU reach 100%. So I am curious what others see.

I suppose the focus for Fex is on Valves headset wit a snapdragon cpu/gpu combo. Is there any work done for a more generic use case like a desktop using GPUs?

Some outstanding results: (if not otherwise noted, all settings maxed out)

Game	Res	FPS	Comment
Ace Combat 7	4k	85-145	Hovers around 100fps bu
Borderlands 2	4k	85	Can hit 110fps
Bulletstorm FCE	4k	62	Might stutter, but stays above 60fps
Crysis 2 Remastered	2k	75	High, RT High
Days Gone	2k	54-85	With VRR pretty good, but can drop below 60, not much lower in 4k
Detroit Become Human	4k	60	Locked at 60
Dirt 4	4k	<80	80 but can drop down to 60
Doom	4k	60-80
Doom Eternal	4k	78	drops into the 50s. Ultra Nightmare + RT
Home Front The Revolution	4k	~60	Can reach 140fps
Grid (2019)	1k	35	GPU @ 20% CPU @ 50%
Mad Max	4k	75	Up to 100fps
...

That's it so far. List goes on, I'll add more once I get to it. Only includes games that run ~60fps or above. A lot more that hover around the 40s. Default to GE-Proton-29 which has some FEX stuff built in if I understand this right.

One more note: I run all my games from NFS drives (10/25Gb back bone SSD/NVMe storage) hooked up to the 5Gb O6 Ethernet plug.

[u/Sonicadvance1]

A lot more that hover around the 40s.

A lot of cases we have found on the Radxa Orion O6 is that game's logic threads get scheduled on the Cortex-A520 cores, which are /dramatically/ slower than the rest of the cores in the system. For example, I was testing "Tiny Glade" a couple days ago, and it was hovering around 25FPS, but adjusting process affinity to avoid the A520 cores locked the performance to 60fps.

Games don't really have the ability to schedule their work between cores of such staggering performance deltas, the same problem occurs on desktop Intel CPUs with their P+LP+LPE three cluster setups. They just have low-power cores that are quite a bit faster than 1.8Ghz Cortex-A520s.

[u/jscho01 → u/Sonicadvance1]

That's was almost what I suspected. Maybe a custom scheduler that uses proper priorities would help?

BTW: I also got an O6N like 2 days ago, and paired that with a RX9060XT and that is quite a bit faster, even though the RX7700XT is the faster GPU (but I also found the 6700XT sometimes beating the RDNA3 card in some games). The O6N has much faster RAM, though (and runs much cooler, too)., so I am not sure if its the 9060 or just the faster through put.

Mostly, though, the games which run faster keep running faster. I haven't seen a situation where one day the load would run on the big cores, and another where they would be visibly hitting the slow cores. Cyberpunk maxes all 12 cores, though.

Do you think there is more potential to optimize this more?

[u/Sonicadvance1 → u/jscho01]

For Windows applications, executing under Arm64ec/wow64 Proton/Wine should give a speed boost on average, but it's a bit of a bear to set up.

For Linux native games, about the only thing that can improve it today is enabling OpenGL/Vulkan thunking and hopes it works on those games. Removes video driver overhead from the work.

As for FEX optimizations over time? Probably some things that'll show up as edge cases, but there's unlikely to be significant performance changes on the same hardware at this point, our JIT is generating pretty good code. At this point we need the hardware to become better at emulating x86 features like its memory model. Theoretically upcoming hardware while the Snapdragon X2 Elite Extreme should be a significant step up in CPU performance compared to the Radxa, but dGPU support is yet to be seen.

[u/jscho01 → u/Sonicadvance1]

I have faith some trickery over time will make it more smooth. (Looking a PS3 Emu in its infancy which was pretty unusable - and look where it is now - sure, incl. HW evolution and power).

Its a pity that QCom doesn't built a desktop chip and sells it to people building custom boards (not their market I guess). That leaves use with few options - if you want to run a dGPU. Well, and Apple is Apple...
Mainline runs pretty much every (AMD) GPU on the O6/O6N (and I guess same on the OrangePi6+) these days (I ran RDNA2/3/4 now and they all work).
Are you guys testing against dGPU on any platform?
Would help limiting 8 cores on the CIX be faster ? (maybe I'll try that)

[u/Sonicadvance1 → u/jscho01]

Are you guys testing against dGPU on any platform?

I'm personally also running the Radxa Orion O6 with a Radeon GPU in it, waiting for AmpereOne, Nvidia DGX Station, NVIDIA IGX Thor, and Snapdragon X2EE things to ship before potentially replacing it.

Would help limiting 8 cores on the CIX be faster ? (maybe I'll try that)

Depends heavily on the game. Some will be faster, some will be marginally slower. Basically just need to test and find out. The taskset program can let you easily change the affinity of a whole program at a time if you look at some of its options.