Ok so originally my pc had an Amd 7770, Amd phenom ii x6, and the rest of the parts were parts from HP that I don't know the names of. On that system I was running games like skyrim at 30 fps on medium so after a while I decided to upgrade... I now have an asus mobo, a sapphire amd 7770 1 gb, an amd 8350 8 core, the hp ram from before, a 2 tb drive from WD, a 625 watt psu, and a cooler master hypo evo to cool the cpu, after I upgraded I had to reinstall windows so I installed on top of the previous windows installation to keep my old files, installed all the drivers etc. Then I wen't to try out some games, the first was Thief , I started the game and ran the benchmark. I got 45 fps on ultra. Sadly this did not last as I ran it a second time and got 15 fps. this happens with all of my games, Sometimes this happens and sometimes they're just choppy to begin with, the games I usually play are , Skyrim, bf4, crysis 3, and bm arkham origins... I know these are all very demanding games but the same thing happens with octodad and goat simulator and it's not the graphic setting being to high because if I set it to low I get the same results. I've tried everything from checking cpu/gpu temps and changing fan speeds to reinstalling drivers, nothing works. Another thing to note is that on windows start up Aero effects are acting strangely, it's fine at first then randomly stops, I've tried disabling it but it does nothing and game menus are choppy too as in when it says "Nvidia" it's choppy. Please help, Should I reinstall windows without installing on top of the previous windows or change some setting in the bios or what?