[SOLVED] huge FPS drops - Engine changes?

I have been experiencing HUGE drops in framerate during play.
I cannot really tell when exactly it started, but i would estimate about 4-5 weeks ago.

I am always using latest autobuild, so maybe i incorporated some bad gfx fix with a recent built or whatever?

It started all of a sudden, FPS dropping from decent ~100 to 40 or so for some dozen seconds and going back high, happening quite often now.

I already reseted the config to default, used the Minimum settings even (when Ultra have been playable before), chosed Net speed settings high and particle amount whatsoever low, all right.

I even started to roll back my Nvidia drivers to some older release i knew everything played fine.

I checked other running process, cleaned the system, checked vor virii, rootkits and whatsnot.
I even checked temperatures of cpu and gfx cores etc, all to no avail.

So right now I am at a dead end.
Older Nexuiz delivers a whopping 200 FPS on highest settings, whilest new Nexuiz crawls at (timedemo'd) 60-100 on LOWEST but drops to sudden 30-40 while playing.

I dont see a connection to anything.

Any suggestions?

[saxnbower]noteven/nosound

(AMD Athlon II X4 640, nVIDIA GeForce GTX 460 - 768MB, 4GB DDR3 SDRAM)

Can you test 0.6 and see if that works well for you? Or maybe build an older (but more recent than the 0.6 release) state of the engine from git if you're capable.

EDIT: Wait, what is it about Nexuiz in your message?

Older Nexuiz delivers a whopping 200 FPS on highest settings, whilest new Nexuiz crawls at (timedemo'd) 60-100 on LOWEST but drops to sudden 30-40 while playing.

Yeah please define 'new nexuiz' cause if that's not xonotic then you have other issues not game related.

Oddly enough I now seem to have (perhaps maybe) found a solution, although I not really know how.. ^^

I noticed something about the shader clocks sometimes go low (say 100Mhz) and wondered about that.
I read in some BF3-forum about simliar problems and one considered placebo 'fix', which meant cleaning profiles within the Nvidia control center.
Now i have done that three times before, always rolling back some 0.2x driver revs, with option checkbox "clean install" marked, which should have done exactly that, but appearently didnt do so?

Anyway, right now i enjoyed half an hour of flawless gaming; i am truly astonished now.
The bad behaviour goes on for weeks, and then, right after i've posted in here and guess-blamed the engine.. it works again. Jeez.

(I was downloading 0.60 btw, but got bored waiting for its huge torrent download - still 15mins to go - so I will try that later, if the problem occurs again.)