C2D Q8300 Bottlenecking HD5850?

[Forsakeneyes]

Hello,

Recently installed a HD5850 along with a clean Windows install but benchmark scores don't seem to be a lot higher than with my 8800GTS. Could the CPU be the culprit? It is running at stock 2.5Ghz.

Thanks!

 

[Forsakeneyes]

Other important specs:

500Watt Spire Rocketeer PSU
Gigabyte P35-DS3R F9 BIOS
4GB DDR2 800Mhz (4x1 Corsair XMS)
2x 160GB Seagate 7200rpm HDD's running in RAID0