40-50 isn't thaaat bad but you should try to keep it in the 30's-40's. Under a full load of seti and UT timedemo for about 5 hours my 550e@733 gets up to 46c. It is supposed to get up there in the temps tho when it is running a decent load. Now that isn't bad either but you want to keep that thing as cool as possible. I say don't worry but try to get it cooler if you can. Have you tried any thermal paste?
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