I'd like to know if anyone using a single core processor has noticed any
significant improvement in performance after upgrading to Windows Vista or is
it only those with Dual Core processors that are noticing significant
improvements to performance? (Please, this question is for those who were
previously running XP with the same hardware, if you’ve increase your RAM or
made other hardware upgrades then it's hard to determine if your performance
improvements are really due to the new OS.) Thanks

Relating to this issue you may also find this article by Christopher Null of
interest: http://tech.yahoo.com/blogs/null/13487