Do you play Battlefield2? If so what settings do you use in the nvidia control panel? Since upgrading from my x800 the game now takes 2 - 3 times longer to load up a map and when I get in the game it runs really bad for the first 2 - 3 minutes of every map. At first it ran REALLY bad all through the game then I altered a couple of settings in the GX2's control panel(I forgot which ones now) and that has left me with the problems described above. My pc is AMD 3800, 1gb pc3200, sata hd and the 1gb nvidia card. I am sure it should be playing the game a whole lot better than it is. All other games work fine.
make sure you download the newest forceware for the card. and if i remember right there is a sli patch for bf2.