About 67f.
73% fan on my GTX 470 is, in volume, approximately the same as my 5870 was when I ran it at about 40% give or take a little, but a lower, gentler noise rather than the hairdryer-whir in pitch of the 5870.
Yeah, it's actually sorta surprising how overclockable these things are... I think the GTX 470 especially represents a good value.
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