Aqua-Soft ForumsI found some amazing info here:
http://winhistory.de/more/386/xpmini_eng.htm
Look this and believe or not... 
XP Minimal-Requirement-Test
HOLY CRAP.
Look at the outcome for the PC with 20MB RAM and 8Mhz
The boottime of this system is extremly long, 30 minutes!After 13 minutes you can see the first icons, but there are 17 minutes more,
where you can do nothing, before you can start "working".
I think we know who has a lot of free time on their hands. <.
taking backwards compatibility to the extreme... maybe they should try playing hl2 on it as well 
for a few years i was running xp on a 266mhz 64 mb ram p2 with a 1Gb hard disk. it was quite zippy, honestly
HOLY CRAP.Look at the outcome for the PC with 20MB RAM and 8Mhz
sure, 32bit processors can only handle 4gb of ram, the only advantage 64bit has is to have up to 8gb (the main advantage), servers that have more than 4 or 8 with 64bit use "Virtual Memory", so it is expected to not run as well
@thehundredthone, haha, but i bet once you upgraded it was even zippier 
@astyanax: i wish i could say that, but i think the performance increase is not that great unless you tweak it here and there
although the extra 119 Gb makes good for hibernation
all i can say is oh my god :|