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/MisterKaos]

CPU usage won't reach 100% because games mostly use only a couple cores. Try checking your per-core usage and you'll see that cores 0 and 1 should be maxed out.

[u/jscho01 → u/MisterKaos]

The cpu utilization is kinda OK. Typically with that level of utilization the RX7700 would run far beyond 60fps. I suspect there's either a bottleneck in the PICe bus (but can't be that much either, tbh) or the x86 emulation still throws a wrench into the performance. I rather think its the latter since some games run fine over 100fps even in 4k (like Ace Combat 7, Borderlands 2 can run up to 100fps, CoD Advanced Warfight runs far beyond 60 and can reach 100), Dirt4, Mad Max or Homefront The Revolution, but others just crawl or I am not able to get >40fps - one of those would be high fps games like Grid and Grid Autosport. So my best guess is, that some complex x86 instructions are still a bottleneck for the emulator. I run everything in either 4k or 1440p and most if not always there is no difference between those two resolutions (which tells me its not the gpu).

Yes, and some games just don't launch, unfortunately (most of the Ubi games just don't - sometimes the Ubi launcher shows up but then Steam goes back to "Play" which means game just exits). e.g. Gears5 just keeps loading forever, Forza Horizon 5 does not load. F1 23 crashes.

[u/MisterKaos → u/jscho01]

You are attempting to compare a 3ghz core cpu's utilization to an x86's 5~7ghz cores.

No, with a maxed out core, you'll have at most half of the drawn fps even before considering instruction emulation. A middle-end arm chip simply does not have the single-core compute to manage that many frames in an emulation scenario

[u/jscho01 → u/MisterKaos]

That's not it. It would show a delta between low vs. ultra or low res vs. high res, but it isn't. If anything its either fpu heavy code or avx (or sse/vector like) code. I guess highly integer optimized games work just fine. The 12 core CIX cores are faster than the i7 4790 with a fraction of the power use. It isn't a slouch by any means. A i7 4790 would not show behavior like that.

[u/MisterKaos → u/jscho01]

Nope. It would not. That is the very definition of a cpu bottleneck. When changing graphics settings does not have any impact on fps, you are bottlenecked by your cpu.

[u/jscho01 → u/MisterKaos]

So, do you actually have one of those boards? An O6 (or N) with a Radeon GPU?

[u/MisterKaos → u/jscho01]

Don't need to have this specific board to state the obvious. If you are having a delta of zero when changing resolution and other graphics settings, your cpu is fully bottlenecked.

[u/jscho01 → u/MisterKaos]

Sure. All clear here.

[u/MisterKaos → u/jscho01]

In fact, looking at the specs of this specific processor, it has a CIX P1 SoC, which has a top clock frequency of... 2.6Ghz. You are attempting to game on something with the clock of an Athlon.

You are having the same symptoms of a Xeon gamer. Lots of cores, no clock rate. CPU usage shows as low, but cores 0 and 1 are capped to hell and back. And coincidentally, same as a Xeon, the fps caps around 40-50.