Seems to me 0981 is the optimal run number, any higher there is issues. Any lower and I'm just doing myself a disservice. They are quite picky about being crowded on cheaper powered hubs. Though right now for me it's an illusion to be running at 2ghs each and I don't understand. Maybe just how I read bfgminer.
http://i.imgur.com/2ezT7mx.pngI guess I really don't understand the numbers in the middle column. First 2 show about 2ghs then the 3rd shows what I guess is the average. But it's the 3rd one that the pools see. I should be at 10gh/s but it's more like 7.5gh/s in reality.
How long have you left them running? It can take hours for it to even out on mine...
I managed to find the following explanation of the three columns on google, which helped me understand things a bit better (still getting my head around it all though!);
"5 second exponentially decaying average hash rate / An all time average hash rate / An all time average hash rate based on actual nonces found, adjusted for pool reject and stale rate"
