My 6770 was running about 76c at stock. This was okay back when we were allowed to use lead in solder! But a really hot summer killed it on that damn EU lead free solder that was also killing early XBOX 360s and PS3s with "ring of death".

My 5830's ran at 60c, and my 7850's run at 50c!

Really the 6770 sells for the same price as a 5830 and that's a much faster, cooler, quieter card with no OEM driver issues.

Video of a 5830 running Battlefield 3 in 1080p Ultra 0xAA with FPS and Temp counters.
http://www.youtube.com/watch?v=EjCOwK3VJDc