I have a problem, claymore's miner show on my rig doing around 2070h/s, but on dwarfpool show my rig doing around 2800h/s, so which one is right?
Claymore shows you the physical hashrate. Pools show the hashrate based upon the submitted shares (usually) in the last 5 minutes. This value may be larger or smaller than Claymores value, because submitted shares are based on luck.