New graphics card, but computer is still slowing down...

by AndrewRich - 4/15/10 6:35 PM

So I'm running an AMD Phenom x64 quad-core processor (3.5 gigs each) and 4 gigs of Corsair Dominator DDR2 memory with an Nvidia GT8300 GPU on Windows Vista Ultimate 64-bit with a 750 watt Corsair power supply running it all. I just installed an MSI N250GTS 1G OC graphics card, so why the hell is my computer still "stuttering" when I run a large graphics app?!!!! I updated the card BIOS and the mother board BIOS, and of course updated all drivers, memory checks out fine and there are no hardware conflicts and on top of it all I even overclocked the processors and the graphics card temporarily, but to no avail....I'm so confused - what am I missing?!?!? Help!