Asus Extreme 7800gt , help pls .

Hey there , just bought an asus extreme 7800gt today , it seems to work fine in 2d applications . but I've run FEAR and 3dmarks and have the same problem , that being the frame rate starts out very nicely but dies in the arse to about 2fps.
My computer :
Dell 4700
Intel 915g mobo
pentium 4 3.0
1.5gig of ram (2x 256mb + 2 x 512mb)
can find out other specs if need be .
Any help much appreciated ... thanks .

 

Yikes! No freaking clue. WILD ass guess: do your memory speeds match? Also, maybe you need upg of video card?
Cheers,
Bob

 

it was just a heat issue I think , as my sound card was pretty much up against it , not allowing any fresh air through it . It seems to be ok after shuffling some pci card around .

 

And what drivers are you using for me i have problem with the latest forceware 81.98 so i went back to 81.95 and fix my problem just upgrade two to a geforce 7800 GT 256 megs