I agree with khayos - You might need to consider upgrading your computers or reducing the # of toons you are running.

I run 4 toons on my 2nd comp w/keyclone and my main char on my main comp. I made sure to set the video settings for each char on the 2nd comp as low as possible and turned off the sound. I never have an issue with fps expect when i enter a major city - which I try to stay away from, or if i have to, I go 1 or 2 at a time.