My pc contains a xfx ati readeon 6950 2gb gddr5 graphics card, amd phenom x6 1060t processor,psu xfx 600 watt,asus motherboard.I had been using this for more than 3 years.Now I am having over heating issues when playing high graphics games like watch dogs,AC black flag etc .After 30 mins of playing the pc hangs and the restart button doesn't even work.I have to turn off the coumputer untill it gets a little bit cool else it dosn't even start.I don't have any kind of custom cooling system installed in my cpu.Just 4 numbers of low speed fans which comes with cabinet.Suggest me any kind of cooling system/water colling system that saves my cpu from getting over heated.Thanks.