good lord I have the same model as you, I have it highly oc'ed and temps never go above 70c, you must have a weak fan profile is what im thinking, also you probably have bad case airflow, with these two factors at work I can see you temps getting like that
His case seems like it would have good enough airflow.It's got x2 120mm's for front intake and a rear 120mm exhaust.Of course their are a few other fan mounts on the side and the top.I suggest you populate those if you can.
81 C is not enough to damage the card, but curious why mine is 30+ degrees hotter than this review. My chassis is Corsair Carbide 400R, and I have 3 inlet fans and 2 exhaust fans (plenty of airflow).
Thanks for your time,
because that review ( and most reviews) are done on test benches and not in a case. I have the exact same case with an evga GTX560ti stick fan and I will hit 84c during gaming but I lock fan speed at 38% to keep noise down. You have nothing to worry about your temps, they are actually cool and unless you decide to stress test your PC everyday ( ) then you won't even see 81c in real world scenarios.