90C is about the max for GPU under heavy 3D load, so 80C without a 3D load is way too hot.
does your video card have a working fan? is your PC's exhaust fan working?
ok, im on the internet and a couple of small prgrams are running and my typical GPU temperature is 80'C.(Remember this is diferent to CPU, I read GPU can hand heat more easily than CPU.)
When im in games like HL2:Ep2 the graphics are reccomended to be very high for my computer specs. But after about 3/4 hour my EXPERTool crashes and A tmperature warning is displyed by NVIDIA with a temperature of over 100'C so I stop playing for 5 minutes and it cools down enough.
If I keep doing this will it destroy my computer in anyway, ive been doing it for some time now and nothing has gone wrong yet. the NVIDIA temperature cut-out is 125'C
Thanks for reading and hopefully helping.