i dont think its the psu. A friend of mine connected yesterday a second psu to check if that was the problem and the computer had the same behavior. As for the drivers they have had been installed and uninstalled diferent versions.
nfsmw, nfs-carbon, oblivion (medium settings 1280X1024), citylife, fear, .....
I always make sure i have a good frame rate (over 40) but even if they go up to 60 or 70 the game doesn´t run smoothly.
The only exception is jade empire special edition, the frame rate is always betwen 28 and 30 and the game runs smooth
Strange...70FPS but doesn't smooth ??
turn the V-Sync ON in the NVidia Control Panel.
try different resolutions & refresh rates.
disable all back ground programs (anti virus, anti spy, etc).
if all didn't help...install a new fresh windows XP (not vista)& before installing anything(except drivers), install one of your games(Need For Speed Carbon for example)& see if it runs smooth.
Unfortunatetly, the GF7 series is weak at Oblivion and Need for speed Carbon. For Carbon, make sure you disable motion blur. Oblivion, hit Tweakguides and dumb down min grass height & grass distance, and also the shadows (turn off self shadows, shadows on grass, tree canopy shadows, in and out shadows to 50%, and set shadow filtering to low.
As far as NFS Most Wanted, there is a stutter-bug with it that affects some people even if it's a high end rig. You can have great framerates and still get hit with the occasional stutter, which varies person to person how frequent it happens. The issue was all over the official forums and as far as I know never fully resolved for many people. Shoot, it affects the XBox 360 version too.