I have had this HD 5770 for over a year. It's been doing fine. However, its peak temperature on load is around 92 celcius.
I have heard that this model is known to be hot (not the hottest) and that above 80 is too hot but GPU can handle 90s as long as it's not over 100. What do you think?
I home-built my PC and just cleaned it last month. Before cleaning, its temp went to about 96. My case is antec 900.
I have intel core i3 520, 8GB RAM, that video card, 1 SSD and 1 regular HDD. I use dual monitor at 1920x1080. Windows 7 64bit.
I use GPU-Z (I think) to see GPU temp.
I would recommend getting some extra case fans or make sure that you PC has proper air flow, no wires blocking fans ect. You dont want a GPU running over 90, mine stays at 60 normally, and that's when Im playing some big games.