Fixing KWin’s performance on old hardware

KWin had a very long standing bug report about bad performance of the Wayland session on older Intel integrated graphics. There have been many investigations into what's causing this, with a lot of more specific performance issues being found and fixed, but none of them managed to fully fix the issue... until now.

Xaver Hugl

An excellent deep dive into a very annoying problem KWin on Wayland running on older Intel hardware was facing. It turns out the issue was related to display timings, and older Intel hardware simply not being powerful enough to render frames within the timing window. The solution consisted of a various smaller solutions, and one bigger one: triple-buffering. The end result is a massive performance improvement for KWin on Wayland on older Intel hardware.

This detailed post underlines just how difficult it is to simply render a bunch of windows and UI elements on time, without stutters or tearing, while taking into account the wide variety of hardware a project like KDE Plasma intends to run on. It's great to see them paying attention to the older, less powerful systems too, instead of only focusing on the latest and greatest like Apple, and recently Microsoft as well, do.