Zink OpenGL-On-Vulkan Ready To Switch To Lazy Descriptors - Big Performance Win

Mesa's Zink OpenGL-on-Vulkan implementation is finally ready to enable lazy descriptors by default, which in turn will mean better performance for this generic OpenGL implementation across many games/applications.

Zink's lazy descriptor handling is to ultimately replace the Vulkan descriptor caching currently used by this Mesa code. The "lazy" descriptors end up meaning much better performance for a variety of OpenGL workloads and after a year of maturing there are no known performance regressions.

Zink lazy descriptor benchmarks I ran last August were already looking great for some games at the time:

Since those benchmarks last year Zink has evolved into even better shape and ready to see lazy descriptors enabled by default.

Mike Blumenkrantz working for Valve on Zink has blogged about the milestone:

"When combined with extreme bucket allocating, this methodology ends up being more performant than caching.

And sometimes by significant margins.

In Minecraft, for example, you might see a 30-50% FPS increase. In a game like Tomb Raider (2013) it’ll be closer to 10-20%.

But, most likely, there won’t be any scenario in which FPS goes down."

This merge request is pending for Mesa to enable lazy descriptors by default. Hopefully it will still merge in time for the Mesa 22.2 feature freeze soon. Once branched I'll be working on some fresh Zink OpenGL-on-Vulkan performance benchmarks.