I've always had the feeling that my machine isn't running as fast as it should so tonight I started running some 3dMark Vantage benchmarks. It seems like I am coming in quite a bit lower than I should be when looking at other peoples scores with similar hardware.
This was my result running a 'Performance' benchmark which I scored P10295 whilst other scores I looked at where 16-20k with same video card, cpu, and amount of memory.
Well the 'not overclocked' is where this is tripping up. Your bottle necking your card really badly. A Q6600 at stock settings isn't going to handle that 4870x2 card. Your ram is also slow at 800hmz. I always felt (but have no real numbers to back it up) that for a you needed at least 1066 for a quad core. But that is just imo.
If you overclocked those two parts you will see a much higher out put. One thing is leading to another.