Zerratastic :
Hi again, I have fixed the lag on APB it was a videosetting. I played it today and id did lag as hell and i went in to the options and I play on 1920 1080 and i change it to 1600 900 and it did still lag even on medium settings and then I saw that Multi GPU thing and i turned it on and lag was gone even on maximum 1920 1080 so i thing it is just settings but Im not sure and after that the lag on minecraft was gone aswell, the FPS is betwen 620 and 180 but some times it drops from 400 down to 120 and that give it a little lag spicke but it is not any lag when I walk around with 300 fps anymore now it is running smooth. Bf3 also runs little better but it is on Ultra graphics, but it is still laggy as f**k on Euro Truck, but I updated it and it is better but still laggy. Btw I have my photos and movies and that stuff on another harddrive (Seagate Barracuda 2TB 7200RPM) i only have Windows, programs and games on the SSD. And i think i maybe will get Windows 8 soon because it run games smoother then windows 7. at least what I have heard from my friend that did just upgrade from windows 7
Windows 8 does help a tiny little bit for your current setup because it takes more advantage of your AMD FX-8350(because it's 8 cores) However, it should not fix your problem as your problem lies around some faulty stuff(software(not a slow OS) or hardware)
Let's make this more clear. Your computer setup is completely fine. It is actually already one of the best gaming PC setup you could build at the moment. (I said one of, not the only one) Your computer can/should handle all the games on the market at the highest settings.
What I recommend is just like hiporc said, wipe all your data on your SSD and install a clean version of Windows. After that, ONLY install the drivers and the games that you're playing.(to help eliminate program conflicts) and test it. If you find no problem at all. that means it should probably be the programs problem. and then install your programs one by one and test your games before you install the next program that way you know which program is causing the problem.
If you find yourself all perfect after installing all programs and games, that could probably be the virus.
Lastly, I do want you to check the video settings on your games. (you have the Geforce Experience, it should not be the problem) Try to find the option to turn off Vsync if that could probably somehow boost your FPS. Well, you already have couple hundred FPS on certain games, that should not be the case. but just checking, why not?
oh and remember to use the Geforce Experience to optimize your video settings though. Sometimes it will not detect your games if you didn't install your games on your system hard drive but rather on your secondary hard drive. Add the location you want the Geforce Experience to scan the games and optimize each games after that.