You prolly only have 2 cores active of the cpu.
Mine did this when I upgraded to the Q9450 from the e6750. (680i, same bios)
Enter the bios, find the cpu area, and enable the additional two cores.
If you have Speedfan, check it, you should have 4 horizontal performance bars, one for each core. If it shows just two, bingo!
My Q @3.2, with 2x 8800 GTX's hits just over 17k on 06.