Quote: Originally Posted by
fieseler 
so while in a game that uses dual core, vista would use the other 2 cores for background processes like services and defragging?
Yes, in a nutshell. The two threads spawned by the game process don't own the processors in any way, and it's still possible for other threads running at a higher priority to temporarily take over, but that won't happen while cores 3 and 4 are twiddling their thumbs.
Quote: Originally Posted by
fieseler This is interesting coz then the 2 cores running the game wouldnt be interfered by the O/S as much.
Each core is like an employee - they'll do whatever the management (the OS thread dispatcher) tells them to do. Obviously, more people means more work gets done overall, as long as the influx of work is sufficient to keep all 4 busy. Hence, a quad can easily out-perform a dual core if there are lots of apps (meaning lots of RTR threads), but its advantage with simpler workloads will not be as marked - if there's only ever one work item at a time, the fact that 4 employees are available doesn't speed things up since they can't share a single work item (thread).