Since you are still using IE5 (YIKES!) on one PC, you must be using Windows.

MS is doing all their dev work now in C++ and increasingly C#, which both then use the Visual Studio compiler. So, if you are using Windows XP on a P4 or an AMD, it's not going to make any user-noticable difference at all. On Windows 32 bit platforms it's now all about PC subsystems and their respective cards and how their memory and drivers are optimized/tweaked.

If you move to a 64 bit capable processor, that's not legacy crippled with the Intel x86 architecture path, like the AMD 64, then you will start to see O/S software and application software start to take advantage of said 64 bit improvements and efficiencies. Will you notice? Who knows... it's not all there for yet.

And I read the WSJ this morning -- that eMachines is killer for 600 bucks: AMD 64 3400+,1GB RAM, 200GB drive, dual CD/DVD +/- RW burners, USB, firewire, card readers and MS Media Center O/S (no tuner card though).

I want one! ^