Well you can always add more voltage to your cpu, get an extra few hundred mhz out of it = bigger score.
It doesn't have to be prime stable to bench - hence me pumping 1.65v in for benching as 3dm06 takes what, 10mins to run? Then I take a screenie and turn the volts back down. No harm done!
Set windows to performance, set high priority to benchmark, turn everything non essential in the background off, try tighten your latencies and squeeze every hertz out, again, as long as they complete the bench and you don't run 24/7 on unstable settings then I don't see a problem.