Your not ever going to have problems with those 2 machines. I tried an experiment with 2 and 3 clients running at separate times. No problems running 2 thru a major town(lag). 3 man...little bit of lag. Your talking about 2 on each machine. You shouldnt have any problems IMO. My main runs 3 and the lesser machine runs the 2. If you have dual core then you can make it even better by putting one on CPU 0 and the other on CPU 1 with Keyclone.