Zink OpenGL-On-Vulkan Can Finally Render glxgears With Great Speed

While the Zink OpenGL-on-Vulkan code within Mesa is close to OpenGL 4.6 conformant and running many OpenGL games at good performance, it's taken until now to see good performance out of the glxgears benchmark.

It took a long time for glxgears to even render correctly on Zink even when it was on to running various demanding OpenGL Linux games... It was just earlier this year Zink correctly rendered glxgears but was doing so incredibly slow.

Prolific Zink developer Mike Blumenkrantz working for Valve has now addressed that performance bottleneck affecting Zink.

Zink had been going through a very slow process when passing vertices into OpenGL to be drawn as a rectangle for glxgears as it resulted in a slow read-back of the index buffer for each draw call. With this merge request pending for Mesa 22.0-devel, that conversion is happening sooner to avoid the costly fall-back.

Blumenkrantz blogged about the glxgears success and now rather than hitting sub-20 FPS he is hitting well above 3000 FPS for this vintage benchmark / test case.