little off topic but for my 8800gtx this was not the case. my gtx @100% fan, case sidepanel open, 20-22c ambient reached 85c under load. the highest o/c i could achieve was 621/1621/999. 648 cc would almost instantly produce the nlvdd error or bsod. 621/1674 would produce driver errors or bsod anywhere between 1-5hours under load.
on water i could achieve 648/1674/999 with 45c load, closed case, 20-22c ambient. this o/c has been completely stable so far.
so with water you can achieve higher gpu o/cs in some cases.
my results
thread
OT: i usually hate any light coming from my pc (even taped up the mobo power on led) but the look of a cool blue led coming thru a plexi block is nice, great job Eddy.