Hello, I have a 768MB ASUS GTX 460 and when I run 3dMark Vantage on the Performance setting of 1280x1024.
My GPU score seems really low. Does anyone have any suggestions as to what the problem could be?
I have a Quad Core CPU (q8400) and 4GB of DDR2 Ram. My Power supply is 400 watts.
Welcome to HWF 
The first thing you should do is installing the latest drivers for your graphics card from the NVidia website.
Thanks, the problem was already resolved on another forum (PC PER). It turned out that for some reason my Nvidia Control Panel was messed up and was running some 3d game content in 2d clock speed mode.
Cheers
The second suggestion is to forget about synthetic benchmarks and focus on how the card performs in real life.
Benchmarks scores will vary from system to system even if the systems are identical. Unless the score difference is say a 1000 or greater,
then there may be a underlying driver, heat or OS issue. Most scores I’ve seen from that card are around 10000.
What other hardware are you running?
Also, the 768MB 460’s have about 10-15% lower performance than the 1GB version due to it’s (amongst other things) 192bit memory.