While overclocking my Sandy Bridge processor, I noticed there was a setting in the BIOS for an alarm to sound when the processor hit "X" temp. threshold.  I set the threshold at a number just piced out of the air.  I am able to do my everyday functions just fine and performance is very good with this machine.  HOWEVER, if I make any changes to my Rendering settings other than the "out of the box" basic Photo View settings, the rendering will cause the processor to trip the alarm.

How hot is too hot for this Sandy Bridge processor?  I am air cooled with the stock heat-sink.