Poor performace with AMD GPU


I’ve been using Zwift on my Surface Pro 7 (10th gen. i5 / Intel Iris+ / 8GB RAM) for over two years now. I had occasional hiccups, until it started to act up last week and Zwift was having problems to reliably connect to my devices and crashing constantly.

I decided to throw together old hardware I had lying around to see if things would run better. I used an 4th gen. i7 and a RX 460, which on paper should outperform the integrated graphics of the Surface.

Zwift runs stable on that system, but framerates are worse. With the surface I can ride on 1080p with ~30 FPS, at 720p I get constant 40-50 FPS, which ok given the small screen.

The RX460 seems not to be able to produce beyond 20 FPS at 1080p, which simply isn’t usable. At 720p I get around 30 FPS, which is tolerable.

What’s going on here? I read that AMD’s OpenGL implementation performs poorly, but does that explain such huge differences in framerate?

Thanks for any insights, cheers!

Are you running one of the more recent AMD drivers since August '22, which claimed to have OpenGL improvements?

I am using 22.11.1, so they should contain the claimed OpenGL improvements.

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A few things to note;

  1. The RX 460 easily outperforms integrated graphics, but in Zwift gets High profile versus Basic, which is a lot more demanding.
  2. The frame rates totally depend on the circumstances - where you were, how busy it was etc. Your Surface on Basic in London, versus your RX 460 on High in Yumezi, for example. Likewise if you were in a group event you were very likely CPU bound anyway, especially on Makuri on the latest update.
  3. Driver version, which you’ve already covered above.

I also thought about wrong or unsuitable profiles might have been assigned to the RX460. I assume that is done by just parsing some driver- or device string? Can I just copy over/edit the profiles to create similar settings on both devices?

Regarding your #2: I did a quick test in the same start area within 10 minutes, population was very similar. I followed a few riders to see how that woudl influence FPS and then just had the camera sitting with me standing around. That shouldn’t be the primariy issue here.

Profile is assigned automatically by the game on loading. It can’t be changed, though you can fiddle with some of the values and turn a few basic features on and off.

If you’ve done exactly the same test on both then you’ve eliminated the CPU bottleneck issue as a factor. In which case unless there’s a hardware issue or some other problem holding back your new setup, all I can suggest is you buy a stronger graphics card because the RX 460 is very weak. The integrated graphics on your Surface is also weak, but it’s driving a far easier profile. Even the iGPU on your 4th gen i7 can do ~30fps in 1080p on Basic.

I see. I’ll fiddle around with the settings a bit and see where it gets me. I assume that the information on zwiftinsider dot com slash config-file-tweaks is still valid?

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Correct, just remember that you can’t tweak a full profile - a common misconception people make when referring to that guide.

I discarded the idea with the minitower, external screen and peripherals. Too much stuff standing around and taking up space. Especially considering the poor performance.

I went back to my Surface and did a fresh install, unfortunately I still got the occacional crash (yesterday one after ~10 minutes, then two hours without issues.).

I went back to Windows 10 so I am able to install the older driver recommended here on teh forums for Intel 10. gen iGPU issues. Haven’t had the time to test, yet. Maybe this afternoon.

Running OBS is probably a better idea.

I had RTSS runnig to cap the framerate at 30 FPS (maybe less stress would help), and also add an overlay. Didn’t help though. I assume the effects are similar to running OBS?

I’m referring to your Surface crashing issues. :+1:

I know, me too :wink:

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Haha, sorry. I associate RTSS with systems containing a dedicated GPU, my mistake. Anyway, OBS is still worth a try. Just have it running in the system tray, obviously doesn’t have to be capturing anything.

I started using Zwift in September 2020. I had a few hickups with ANT+/BT connectivity, but no crashes, that started later. As the Surface was not dedicated, I upgraded it regulary, eventually to Win11.

The downgraded gfx driver falls in that hassle-free time period. But we’ll see. A 45’ testride yesterday went w/o crash.