Hi, My system specs are: Pentium D 2.8Ghz RAM 2GB DDR2 533Mhz Mobo - Mercury PVM7 Pro Version 1.0 nVidia GeForce 128MB 5200FX AGP 8x - No FAN provided by the company 80GB Seagate SATA While playing games, after about half to one hour, game starts acting too slow. While playing, frame rates are reduced and game runs with pauses. I am taking here the example of NFS Carbon. This happens with all other games too. This happens always, no matter CPU/GPU is overclocked or are in their factory settings. I highly suspect this is overheating problem. But when I was trying OCing, I installed a 12mm fan on my GPU's HS(it doesnt have any fans). Then I ran stability test for 4-5 hours, then played games for another 2-3 hours(with this problem) and then shutted down my comp directly and opened the case and touched the HS on GPU(all took 1 min), it was dead cold. I have tested this before installing the FAN too, but that time HS was very hot. So, I am confused. Anybody please help me out. Answer this question too: How to measure the frame rate I am getting while playing any game, say NFS Carbon? Can it be done through any other way than benchmarking tools for NFS Carbon?