Not sure if this belongs here or on stackoverflow... When I run my selenium tests, the cpu usage on the (windows) VM running the selenium RC goes up to 100% cpu usage for about a third of the time. I thought maybe I'm not allocating enough resources to the VM. How much resources would you allocate?
You should not have to allocate a lot of extra resources to the VM. Selenium itself does not need all that much mem.
Are you spawning 10 web browser instances? Or an IE, Firefox, Chrome, and Safari all at once? Are you putting any sleeps in your script, or is it running the test as fast as possible?
I use 768MB VMs with windows home on them. Make sure you dont have tons of junk installed like Anti Virus software or lots of browser pluggins.