It’s been long known that a vocal minority (or perhaps even majority) of Firefox users have had issues with rendering performance on X11, but nobody has quite pinpointed what the issue is.

Recently Nicolas Silva landed a change in mozilla-central to add a preference to allow for disabling the use of the RENDER extension when drawing using Cairo on X11. I’d like to call on any Firefox/Linux users who have been experiencing speed issues to download the latest nightly and go to about:config and set “gfx.xrender.enabled” to “false”. If you could also let me know what hardware and drivers you’re running that’d also be great.