I'd follow what Dark said. Try 50 - 55% and see if you can bear it. Also, see post #217 by pappy . . .
main thing is to not let your temps affect your gameplay and at the same not risk losing your hearing. lol
edit: also, use HwInfo64 to check temps. it will show both core and vrms temps if your card has the sensors for the latter.
Edited by rdr09 - 9/20/13 at 5:46am