https://bugs.freedesktop.org/show_bug.cgi?id=51787
--- Comment #5 from almos aaalmosss@gmail.com --- (In reply to comment #4)
This is not related to cpufreq. I've fixed my governor to the highest frequency and still experience these massive lags.
Since I cerated a startup script for ut2004 that does 'set all cores to performance ; ut2004 ; set all cores to ondemand' the game runs smoothly without any lag.