LINK: 1,2

This employs the method of sending PWM pulses to the STOPCLK pin of CPUs... Pentium MMX to Pentium 4 seems to have it (P4 might have an errata that prevents it from working properly though), and Athlon to Athlon XP has it (can someone confirm if AM2/AM3 has it as well?)...

This seems to be a bulletproof alternative to the silly (software throttling, ODCM, disabling cache) methods that don't work very well in my opinion, as well as the expensive methods (nearly unobtanium or extremely expensive cyrix 5x86 or Via C3 platforms).

Athlon XP seems to be the most attractive option, with the KT133A being a pretty good platform that still supports ISA.

Does anyone perceive any drawbacks with this method? Is there any difference to a stopclk CPU frequency vs a 'natural' fsb/multiplier frequency?

Seems like a game changer to me in the retro hobby if this proves to be what I think it is. Don't get me wrong, I like my 5x86 system, but it took me several years to learn the ins and outs of the thing and I only have three options with setmul on it.