I'm running poclbm and if I close my internet browser, the speed drops to 3,000 khash/s, but if I leave it open it'll be at 170,000 khash/s.
Is there a reason for this? Also, at this speed, how fast should I be able to finish a block and is there a way in which I might be able to go faster?
Current difficulty it will take you 71 days, 9 hours, 22 minutes to get a block, and try overclocking