l4D2 performance problem

So I have a serious l4D2 performance problem. Tried every driver out there and still bleehh. I can play one map fine all maxed out and then the next map I get like 30fps, and the next map I get 20 and so on. So I have to turn down my settings every other map just to play it ok. After I get like 10fps, I go to AAx16 and AAx16 and I can get like 160fps at any res. !?? my fps is all over the place. tried every driver out there, even the one that sager gave me ^^ lol ... and still nada. what might be the issue?
thx in advance

 

do you have SLI? try alt+tabing after a map change to see if your fps goes back up.
http://forums.steampowered.com/forums/showthread.php?t=1028991&highlight=SLI+low+fps
scroll down and you will see its a known bug with multicore ati/ sli nvidia cards and 64 bit OS.

 

I heard that enabling multi core rendering make your fps go all over the place. Maybe try disabling that and check.

 

thx, ERIK. I'll try alt-tabbing. disabling multi core doesn't seem to have any effect

 

yeah its not a multicore cpu problem its a multi gpu problem.

 

ok, alt-tab works. but I'm stuck with those official nvidia notebook drivers as they have WHQL so I can play bluray. lol. the temps are incredible. I played about 3h of L4d2 and my gpus went up to 65C !?? thats like ultra hot for 9262. usually I get 57-58. I get over 70C but thats with crysis bench fully running. ehhhhh, I'm waiting for new drivers.

 

just use one gpu?

it's L4D2, so you should be able to bust out over 60 fps with a single gpu.

 

Its probably just a driver problem. Sometimes my cpu and gpu go up to 80C. If you are worried about temps, buy a laptop cooler or just put a book under it to prop it up. It helps increase airflow for my laptop lol

 

have u tried 186.81 drivers and latest SLI profiles? This might solve ur problem

 

my m8 seems to be having this problem on his desktop, he's got a single 250gts though....

?