This ^ 
Also I am planning to buy Mac Pro in say 1 year so I’ll probebly be asking alot of questions regarding it along with good version that will work on man with no lags.
Right now my version of Adobe Photoshop CS3 starts lagging on vista as I start using my wacom tablet for it. 
Cant figure out whats wrong with it but I am sure it crosses the pixels limit thats why there is a lag..
I know this is an off topic post but still I wanted to add this in terms of getting ones response…