I've been running mamepp .59 on my p2 400 cab for a while, it was slow, and i couldn't play ALOT of newer games.

I recently upgraded my main machine and tossed the p3 733 into my mame cabinet. It still wouldn't play radien or MK2 very well?!
I remebered playing them on the 733 before and working fine, then i recalled i used mame32, i fired up .59 of mame32 (from commandline, just copied mamepp.ini to mame32.ini and ran "mame32 %1" thru glauncher) and raiden/MK2 now run MUCH faster!
What gives? Shouldn't the mamepp with its i686 optimizations be faster, or is it compiled as a 16bit program and mame32 is compiled as a 32bit program?
--Confused