GNOME Shell's Icon Grid Could See Almost Double The Performance

On top of an optimization to lower render times and reduce power usage and fixing window culling as another performance optimization, Canonical's Daniel van Vugt also came across another serious optimization for GNOME Shell's icon grid performance.

Due to hundreds of primitives being recopied from the CPU to GPU each frame, the icon grid performance was being slowed down dramatically. Daniel van Vugt has proposed a change to keep labels now pre-rendered on the GPU rather than having all these unnecessary copies made each frame.

For his Intel graphics system with a 4K display, he found the spring animation went from 20~30 FPS to 30~40 FPS while the peak milliseconds per frame dropped from 45 to 28. Similarly, scrolling the shell's icon grid went from 15 to 30 FPS and the peak milliseconds per frame dropped from 50 ms to 28 ms.

This merge request has this optimization pending for GNOME Shell that will presumably land in the near future in helping GNOME 3.38 even faster.