BF3 frame rate gets chopped in half

[rashal]

Hi guys,

First of all here are my specs -

i7 920 @ 3.3Ghz
CF gigabyte 5870 @ stock
6Gb corsair DDR3
OCZ vertex 2 128Gb SSD
Corsair 750W PSU

I've been playing BF3 since it came out and performance was changing with every new game and graphic patch that came out, but most of the time it didn't dip under 60fps.

Lately I've started recording gameplay and that when I noticed my FPS gets chopped by half (or more) after around 5 minutes of playing. I've tried pretty much every possible way to solve this including -

1) Disabling HT - had a negative effect overall, still having a huge FPS drop after 5 min.

2) Disabling speedstep - no effect.

3) Trying a lot of different driver combination - even though there was a small change in overall FPS, the main problem remained. (used driversweeper every time)

4) Disabling CF. Didn't solve the FPS drop.

I've been monitoring temps and they are all fine, below 80c at full load, CPU stays at around 65+ at full load. The funny thing is nothing seems to indicated any changes once the FPS gets chopped - same load on GPU and CPU, same Vram usage, same memory usage. Also if I quit the game, wait a few minutes and go bask again, I get good FPS again for a few minutes and then it gets chopped yet again... The situation is just plain frustrating.

Any ideas?