Take into consideration that many drivers for Vista are still in early early development stages.
And the fact is that Vista was designed to run on the newer architecture of today's technology, the "now" if you will.
I have come to realize that although my dual-cores are sufficient for my means, they will never compare to core-duo or quad core for that matter.
Though I may sound redundant, I am simply saying, If you want Vista to run fast you have to give it a fighting chance.
Interesting--I had assumed that there it was slower due to a combination of non-optimized drivers as the previous poster had said but also to do with the coding. I'm surprised that the new OS includes even more programs running the background than XP.
I managed to run Vista a lot faster than most benchmarks, killing a lot of services, turning indexing off, themes, etc. Even with that I couldn't run any game faster than XP. Serious Sam II was running as fast so I was impressed because the nvidia beta drivers are still too crappy.
I hope the final nvidia drivers get the performance back as close as xp levels as possible. I'm not expecting FASTER, but at least Equal or up to a 10 % less.
I have a feeling that this post is a murderous rampage against grammar. Corrections accepted!
My experience has been that there is very little speed difference. My games are moving as fast as on XP once I get rid of the services not needed, just like I did on XP (I'm using non-OC AMDX2-5K+ with onboard GPU - not top of the line, but maybe better than average). Plus, after the latest NVidia driver patch, I even noticed that it is just slightly faster than on XP. That would lead me to suspect that drivers are the most important issue that Vista has to overcome.
I never really got the chance to play games on Vista, I had so many driver issues, that I just reformated my hard drive and started over with Windows XP Professional. I am just going to wait for all the major companies to get their Vista drivers out there and then I will try again.