With your system specs, window swapping shouldn't be that slow. Something must be wrong somewhere

Prior to my recent hardware upgrade, I had a very similar spec PC to you, but with a slower Core2Quad (2.66GHz) and lower spec graphics card (8800GTX). Octopus did Window swaps in a fraction of a second. I'm running Windows 7 now, but it was just as snappy back when I was running Vista 64.