2y ago

RADV Ray-Tracing To Become Much Faster With New Driver Code

www.phoronix.com

MR: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24587

tl;dr big performance improvement in ray tracing on AMD cards coming, with the dev claiming a 3x performance boost in Hitman 3.

Linux Gaming @lemmy.ml

poVoq @slrpnk.net

2y ago

RADV Ray-Tracing To Become Much Faster With New Driver Code

www.phoronix.com /news/RADV-Batch-Accel-RT

14 comments

Wait, AMD can raytrace on Linux? All the games I play on my 6800xt have the raytracing graphics options disabled.
Edit: I'm an idiot, I forgot the 7xxx series has actual RT cores.
- You've been able to enable RT on a SteamDeck with the native (Linux based) OS for about 5+ months now. Performance may vary and it's certainly not going to measure up to a 69xx/79xx series card, but it can do about 30FPS on Doom Eternal, at the native 800P screen which is pretty neat for a portable running an APU :-)
- 6xxx does support it, it's just slower than 7xxx. I don't bother because I don't want the perf hit (even with these improvements) as I care more about high refresh rate/resolution support but good to see nevertheless, particularly for future cards where performance will improve further.
  You might want to upgrade Mesa too as I believe at least some of the RT options should now be enabled by default, but I haven't tested myself. And you can force it with env variables, as the other commenter suggested.
- I think you have to start the game with some arguments to enable ray tracing. Atleast that's what i had to do to enable ray tracing in cyberpunk. Game crashed instantly after i turned it on though lol.
- I case you want to try it out, the setting I've used in Steam was:
  RADV_PERFTEST=rt VKD3D_CONFIG=dxr11 %command%
This will only greatly affect games that don't do batching of their own
Edit: I confused AMDVLK and RADV
As great as AMD is with open source (comparatively), RADV has been a singular source of headaches on distro that install it by default. Many vulkan games wouldn't launch and I hear performance is worse than the community Vulkan driver.
- RADV is the default community Mesa driver, made by Valve engineers.
  AMD's own Vulkan implementation is called AMDVLK, which is just a port of their Windows Vulkan libraries repackaged for Linux. AMDVLK usually moves faster than RADV and got raytracing much earlier. And even though RADV added raytracing as well, RADVs raytracing is much slower than AMDVLK. Maybe this changes will finally close the gap?
  
  RADVs raytracing is much slower than AMDVLK. Maybe this changes will finally close the gap?
  One of the commenters claims this:
  the perf uplift from this PR is huge in a few games, out of the ones I own lego builders journey gets a 2x improvement in performance. Control gets an additional ~5 fps at 1080p, Minecraft RTX (education edition) gets ~10 fps more. When paired with the monolithic pipeline MR it completely blows amdvlk out of water.
  Tested on my rx6800.
  So hopefully that is the case. I'll add that AMDVLK vs RADV has been pretty mixed over the years, and there have been times where RADV has been ahead (particularly with vkd3d-proton support) and usually catches up to and exceeds AMDVLK performance, with the exception of RT.
Hopefully for Steam Deck too
- You'd expect so, but I wouldn't expect miracles. It will vary game by game as well, as only certain types of RT implementations will benefit from this boost.
- It probably will, but I doubt you can do any serious raytracing workloads on the Deck without sacrificing performance and battery life.

14 comments