Ok, so I took the plunge today and upgraded to a quad core machine and i'm playing around with processor affinity settings. I'd like to get some up to date feedback on what people have tried. I see mostly settings for 5 boxing. Right now i'm trying out:

Main: Core 1 & 3 (processAffinityMask of 5)

Alt 1: Core 2 (processAffinityMask of 2)

Alt 2: Core 3 (processAffinityMask of 4)

Alt 3: Core 4 (processAffinityMask of 8 )

Another note: I'm running the 4 on a 1680x1050 monitor with Main 1 at 1200x1018 resolution and all the alts at 480x339 resolution if that gives some better info.