A person who can overclock. An overclocker is awesome.
Shroomer is an overclocker.
An idiot who cannot accept that the people who make the hardware know more about it than they do, and cannot accept to just have things running a tiny amount slower and lasting a whole lot longer, which is generally cheaper in the long run (if you want faster pay more - your only going to end up paying more when you fry it)
Overclocker - its mint look how fast it is
Sensible person - your frying it
Overclocker - no i'm not theres a fan
sensible person - yes but the heat stress will shorten the life meaning someday it won't work