While I used to be a PC gamer years ago, I haven't really played a lot of PC games since 2009 when I got a PS3 and X360. The only game I played on the PC till recently was Mass Effect 2 and that game ran just fine.
However, over the past year or so, every time I have played a PC game, the graphics card fan gets really loud and the PC shuts off. This happened with Dragon Age II (March 2010), Star Wars: The Old Republic (Dec 2011) and now Diablo III which just came out. Even if I reduce graphics settings to the lowest possible, the problem still occurs.
I did some digging in the AMD Catalyst program and saw that, even when idle, the graphics card temperature is 80C+ and when gaming it jumps to 100C+! I opened up my case and see that the graphics card fan, CPU fan and case fan at the back are all spinning. I did notice that the graphics card is right at the bottom and the fan is blowing the air right there so it might not be going anywhere and just centred around the card. I'm not sure if there is a fan at the front of the case blowing air in, but I certainly didn't feel any air blowing in at the bottom. I haven't figured out how to take off the front cover to check if there is a fan at the front.
Does anyone know what could be causing the overheating of the graphics card? and if so, what the potential solution would be? I'd rather not have to get a whole new system just to play Diablo. I would rather just replace the graphics card if that is where the issue lies. I just want to make sure the issue is the card and not the airflow in the case.
Well you should know that a 3 years rig will for sure get tons of dust, try to use brush and clean inside the case, remove the GPU, clean it very well, if you have at hand some thermal compound change it(you gotta see a tutorial how to dissemble a GPU's heatsink) and also adding fans to your case will help a bounch
a HD4850 is still capable for light gaming these days, try to save it doing that a deep clean up sometimes do wonders...
If the problem persist and you dont have to change your GPU, get it back to life buying an aftermarker GPU cooler... for $20 sometimes is worth enough. But also getting a new GPU cure the problem from its roots...
I highly recomend you adding case fans and/or get a case like this