http://bugs.winehq.org/show_bug.cgi?id=23578
--- Comment #9 from Kfir Itzhak mastertheknife@gmail.com 2010-07-10 07:59:24 --- (In reply to comment #8)
Same problem here, only I do not have to restart TF2. It starts randomly, suddenly drops from 50 - 150 FPS down to (suspiciously constant) 7 - 10 FPS and after a few minutes (2 - 3) suddenly climbs back to 50 - 150. Rinse and repeat.
I haven't tried waiting for 2-3 minutes to see what happens, i will try that sometime.