Useful Firefox debug feature

[Ernst Sjöstrand]

Could be useful when debugging bad Firefox performance:

http://www.hackermusings.com/2012/05/firefoxs-graphics-performance-on-x11/

"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."

Regards
//Ernst