interesting enough, Windows Vista 64Bit Editions actually run 20% slower than the 32Bit editions. The positive side to the 64 Bit Editions however is that it supports unlimited amount of Memory, Cache and Graphic Memory while all 32Bit editions only support upto 4Gigs worth.
Yes you heard that right if you didn't know already; Say you have a 2.5Ghz processor, 2Gigs of RAM and a 512MB Video Card. You are pushing 5Gigs worth to your computer, Vista 32Bit can only read 4/5. So your loosing
For me, I have Windows Vista Premium 32Bit..
I have a 1.6Ghz Processor
I have 2.5Gigs of RAM
and a 256MB Video Card
So I am pretty much loosing 512MBs somewhere
Also, some people will claim that Vista is a memory usage hog. Well, with my Vista at "idle", I am only using 150 more Megs of RAM than I did with XP SP1. If I had SP2, I think it would be par because the security options SP2 brought slowed peoples computers down even more than SP1