CudaMiner questions

[ltcn00b]

I have started using cudaminer and have a few questions. I am using nVidia Quadro 600s and individually, I can get ~450 khashes/s but if I try to run them at the same time, it cuts them in half. The two configs that seem to work best for me are ( -l 48x5 -C 2 and -l 54x5 -C2 ). Is anyone else having the same problems?

Below is a screen cap of my results:

http://imgur.com/9ehVS7j