Hi, Sorry for the long post but I wanted to provide as much info as possible for a better solution. I have been experiencing strange clicking sounds [please see link] coming from my XFX HD 4850 lately [or it can be from PSU?]. I have been using this card since 2009 [5 years]. It used to be very rare, only at bootup, but ever since I have started playing Bioshock infinite, it has become much more frequent. Initially I did not get any problems playing, but last time I could only manage 1 hr and then 30 mins before pc crashed. Today when I started the pc, there was not any of that sound, but after 40 minutes the hideous sound started and after few seconds pc shutdown. This happened again and again with shorter time frames. Interesting thing is I did not even played the game, was only browsing the potential problem on the net. Turns out it can either be: -Some hindrance in fans spinning -Coil whine -PSU problem I couldn't pinpoint the exact problem, I tried listening to it very closely, could only guess that it was coming from gpu, it also seemed very hot. Using GPUz, I started monitoring and gpu temp went from 60-70C range to 119C within 25 minutes before it shut down! So it seems gpu is the reason. I put a bit of load [23%] on gpu by emulating a game in pj64 during that time. I had got my power outlets checked by a voltmeter few days ago, the electrician said they were fine. My desktop airflow is good, never had a high temp problem with my cpu and 1 side of the cover is always open. My questions are: -Can I underclock my gpu so that it consumes less power? -Do I need to install ccc, since I haven't earlier? -I used an air blower a couple of months ago and also cleaned the gpu with a brush, did'nt find much dust or any object blocking the fans. I can't rma since I had a bad time doing that in the last few times[other h/w, long wait]. Also I don't have a built in gfx with this build. What do you suggest? Thanks. Link[screens and audio]: http://s000.tinyupload.com/index.php?file_id=72637166005395936235 GPUZ min/max temps: Date , GPU Core Clock [MHz] , GPU Memory Clock [MHz] , GPU Temperature [°C] , Fan Speed (%) [%] , Fan Speed (RPM) [RPM] , GPU Load [%] , GPU Temp.(DISPIO) [°C] , GPU Temp.(MEMIO) [°C] , GPU Temp.(SHADERCORE) [°C] , Memory Usage (Dedicated) [MB] , Memory Usage (Dynamic) [MB] , VDDC [V] , 2014-12-03 08:50:03 , 165.0 , 990.6 , 64.0 , 57 , 1114 , 0 , 64.5 , 68.5 , 68.0 , 8 , 8 , 1.258 , 2014-12-03 09:22:55 , 165.0 , 990.6 , 119.0 , 100 , 135 , 9 , 119.5 , 123.5 , 121.5 , 30 , 30 , 1.258 , Update: After I cleaned my pc again with air blower and also the gpu separately, tested the system. Starting temps were better [from 60c instead of 75c] and biggest difference was the dramatic reduction in fans rpm [previously 262 and now 50-70 rpm] and noise. But bad news is during those 15-20 mins, the gpu temps kept rising again [even at 0% gpu load], and once I put a bit of load on gpu [15-20%, via pj64 emulater] it rised to 120c before pc shutdown again. So does it means I have to apply thermal paste too? Or can this be fixed if I update the gpu driver? Please, any solutions/suggestions wil be really appreciated.