> Curious what your results would be with a Blue or even better a Black WD hard drive.
It's irrelevant to the question at hand. The original poster is comparing Windows XP x64 Edition to Windows 7 64-bit. The point is that with the exact same hardware on both, he's seeing performance differences.
But since you brought it up, unless you're streaming huge amounts of data, there's very little real-world difference between a 5400 rpm drive and a 7200 rpm hard drive for most users other than more noise, heat, and energy consumption with a 7200 rpm drive.
The ideal setup is a small-ish SSD boot drive for the OS and apps for fast booting and app launching paired with a large quiet, energy efficient "green" drive for data storage.
This is what I have in my arcade cabinet PC and it works swimmingly.