video memory with boot camp

Hello, I've been looking to switch over to a MacBook after using a PC for many years and I want to dual boot with XP using boot camp. My question is, how much shared video memory can I have if I'm using XP with 2gb of ram? I've heard with 2gb of ram you can get 220mb, but I'd like to get a second opinion.

EDIT:
Forgot to mention that I'm wondering about the video memory if I'm using XP, not OSX since the shared video memory is 64mb for that.