75-80°C for GPU core? Isn't this extremely high? Grafic card realy hasn't a fan since it is silent type - big heat exchanger, but it came like this directly from biostar.
The system (PC) came as plug and play - so I expect manufacturer (seller) thought about hardware compability, aslo I wanted a silent version of graphic card and special silent fan/cooler for CPU, since my PC is in my room and I don't want it to be loud. There are only two fans - one iside power unit and one on the CPU cooler. CPU and system/power temps are very low compared to the GPU temp - two times lower. Also the BIOS setting for cooling are set to SILENT mode, but I don't know why I see only a CPU fan data - like main fan doesn't have speed control. Also the strange thing is that in BIOS you can only set SHUTDOWN temp value for system (it is set to 60°C), however you can't set this for CPU or GPU. So if CPU or GPU temp values will raise (fan failure) the chips would be permanently destroyed.
System in bios means cpu. It's the temp of the outside cpu casing around the core. And 60 seems about right for that, as the core itself will always be 10-15 degrees hotter than the casing, and most modern dual or quad cores have a T-max around 85. Look in your graphic driver control panel. Is it nvidia ? Should have a section showing the temp and threshold setting. Don't worry about overheating. It will have a failsafe, just like your cpu. So I wouldn't worry about the gpu temp. As I said, it's not abnormal for a silent graphics card. Mine has a threshold set at 95 degrees at default, so it can take it.