I have just tried Bioshock 2 on 2 different PCs.
PC1 - Q9550 GF8800-512Mb 4GB ram XP32 Creative Audigy 4
PC2 - Q9650 GTX470 8GB ram XP64 Creative XFi Gamer
As expected the FPS is better on PC2 but when I pan round the screen on PC2 is very jerky but the screen on PC1 is very smooth. Also, during the initial startup video, the sound chops on PC2 but plays perfectly on PC1.
Similar problems occur on other games tried on both systems and the link always seems to be:-
XP32 = smooth, sound perfect
XP64 = jerky, sound choppy
Does anyone have any ideas?