My main machine here at home is a single-proc 2.4 GHz machine with 3.0 GB of memory. Vista Ultimate has always run slower than my XP install; I just thought that Vista itself was slower than XP on similar hardware by nature.
I recently purchased a second single-proc 2.4 GHz processor to upgrade a backup machine that I had (my ArchLinux box). It only cost $20 (including shipping) to upgrade the 1GHz Celeron to a 2.4G P4! 🙂 The backup machine only had 512 MB of memory, so I decided to pull 1.0 G from my main machine to use in the Linux machine.
Interestingly enough, my Vista install seems to be running much faster once the memory was dropped to 2GB. Maybe it’s subjective, but it really feels much faster. I do know that all memory chips were running dual-channel at 800MHz, so I don’t think that is the reason. Maybe the two 1.0G chip matched set didn’t quite “match” the two 512M matched set! 🙂