Hi, I have recently switched from E8400 & HD 6850 to Q6600 & 7790. Second duo should be somewhat faster but in 3d mark 06 I am scoring lower than before (cpu score is better but graphic/overall lower). Difference is cca 18k vs 16k total.
With newer hardware, it is usually best not to test with old benchmarks like 3d mark 06. Get something newer to test with, like 3dmark vantage or 3dmark 11.