Vmware SERVER 2 CPU HELP

Hello!!

I'm using Vmware server 2 on my HP Proliant ML 150

I have XEON 2 cpu's

But i can assign max only 2 cores (from 8) to my guest virtual machine.

So i have problems with perfomance on virtual machine.

Can i assign more cores on my guest virtual machine(like ESXI)???

Thanks for help!