Mesa 20.1's RADV Lands More Performance Improvements For Recent id Tech Games

A number of recent id Tech games (though seemingly not DOOM Eternal) have seen another performance optimization with Mesa 20.1's RADV Radeon Vulkan driver.

ID Tech games like Wolfenstein: Youngblood, Doom (2016), and Wolfenstein 2 should be seeing better performance with the very latest Mesa 20.1-devel Git code as of today for this open-source Radeon Vulkan driver. This comes after various Mesa RADV improvements in recent days centered around the new DOOM Eternal game under Steam Play. All of these recent ID Tech games can run nicely on Linux thanks to Valve's Steam Play built off Wine/Proton.

The latest RADV optimization should help in the area of around 8% better performance at least from Radeon RX Vega tests conducted by Valve developer Samuel Pitoiset.

ID Tech engine titles making use of Vulkan stand to benefit but due to very specific behavior but it sounds unlikely other engines/games will benefit:

This improvement is because Youngblood uses GENERAL for the main depth-only pass and TC-compat HTILE is now enabled with GENERAL if we know that we are outside of a render loop. This obviously also reduces the number of HTILE decompressions from/to GENERAL.

Note that Youngblood violates the Vulkan spec regarding render loops because they are only allowed with input attachments. Expect possible rendering issues if apps use render loops with the wrong way (ie. without input attachments) because HTILE might not be coherent if a depth-stencil texture is sampled and rendered in the same draw.

Mesa 20.1 with this and many other RADV improvements should be out as stable around the end of May.