From when my PSU blew and took my precious ,I5 2310 processor and motherboard ,along with it ,I now have temporarily replaced my MSI motherboard with some Esonic shit and Processor with Intel Core 2 duo E6750 (Full of shit).Still I have my GT 640 2GB with me.So to game I loaded few high end games (I knew I would get Loads of FPS drop than before) like GTA 5 but I get 25 FPS at most at low settings and a major FPS fluctuations to 1-5.And Even I loaded other games like LA niora at low settings and it lags at even loading screen.What is Wrong Please Help me.(I used to get 40-50 FPS previously , most of the settings at High and even very high in GTA 5)