Originally Posted by clocker
You are missing something.
Extreme overclocking is a "sport" that begins and ends with liquid nitrogen.
All of the PCBs and associated parts are sprayed with a conformal (i.e. "waterproof") coating and sealed with dielectric grease.
The rig is turned off long before the ice has a chance to melt, so I'd guess it survives most of the time.
Clearly, this is the extreme end of the cooling spectrum with few participants and no pretense of anything save breaking records.
Back it down a notch and you come to the phase-change crowd who are essentially using refridgeration units to operate in the -30 to -50c range constantly.
The Vapochill series is probably the most popular unit and they show up in the classifieds for around $400-600 depending on the spec.
Condensation does become a real problem for this group as they are running the units much longer than the nitrogen guys.
The cooling socket is sealed to the motherboard with foam and grease and the backside of the motherboard is heated to prevent water from condensing. It's pretty common to see highly clocked chips running at -40c for days on end with these rigs.
And you thought I was nuts.