GPU running to hot?

Okay so I just got a new ATI Radeon HD 4670 DDR2 1GB (most cost effective for my budget) today installed it everything went fine. So I opened up GPU-Z on one screen (I have a dual monitor set up) and loaded up Tropico 3 on the other. It's running at 77.0 degrees C when I play the game. That has got to be too hot for my GPU right? On idle it runs 54.0 degrees C. So is that too hot for a GPU to run? I one don't want to burn out or crash my computer so if you have any ideas of why it would run that hot please do tell me or if that's not too hot let me know as well.


CPU----AMD Athlon 64 X2 Dual Core 6000+

GPU----ATI Radeon HD 4670 DDR2 1GB

Memory----2GB DDR2 RAM

PSU----400W

HD----SATA II 500GB


Thanks