k9n sli plantinum problem

have two 7950gt in sli but when i play cs 1.6, i'm getting about 60 fps and when i play cs:s i only get about 50 fps. all the settings are at 1280x1024 w/ vsync off and other stuff set at medium (2x,4x etc)

here's my system
msi k9n sli platinum
amd 64 x2 4200+
2 gig of corsair valueram memory at 533
sata hd
two bfg 7950gt oc
ultra vseries 500w ps

my computer is running windows x64 professional and i've installed the latest drivers. i read for reviews of the gpus that i can expect around 100fps for hl2 and my friend has a 7900gs and runs cs 1.6 at 200fps constant no problem.

do i need to turn on anything in the bios or is it some other problem?

i should also add that i had practically the same fps from when i had a 7600gs sli instead of the 7950gt's