4.5 is generally easy for most Sandies. My 2500K did it for its entire lifetime* on (iirc) 1.32v without a problem. Usually just leave all other settings on Auto, set multiplier to 45 and reboot.
See what voltage the chip gets on Auto, then try chipping it down to reduce temps.
Anything above 4.5gig is 50/50- it'll do it or it won't. Oddly, my old one would boot to Windows at 4.7 and 4.8 (not stable, though) but not 4.6 for any money.
I think your chip is fine, your ambient air temp of 30C is why you're a little warmer than you should be. Can you try with a window open?
Also- Prime95 is not a realistic benchmark, it puts undue strain on a CPU which it would never be called to do in general use. It's not really recommended these days.
*It's still alive today, in a friend's PC, chugging away happily at 4.5GHz...