Both Mac and XP run slowly after initial install

I just installed Parallels 5 on my brand new Macbook pro 2.66 Ghz Intel Core i7, 4 gig ram, 512vram.
I upgraded from a 3 year old macbook pro and parallels 3.
The new setup is running xp in boot camp partition, same as before. With the new setup both the PC side and Mac side are running slower then my old machine did with the same setup.
I am also using my mac in closed clamshell mode running a 30" monitor 2560x1600 in coherance mode.

Current configuration is:
Using 2 processors for XP, 2000mb on main memory

Hardware:
Video memory: 256 3D acceleration on, enable vertical sync checked

is there anything in options that should be checked or unchecked to help improve speed of booth.
any thought would be appreciated.