Major fps drops while playing games

Since I got the old gpu (AMD Radeon 6950) and the new power supply (700 watt) from my brother I have been having these problems. Diablo 3 had some fps drops while engaging a big wave of enemies and sometimes my computer had some problems that programs weren't responding.

I actually wanted to upgrade my computer for a while and was hoping to fix some of my problems I have been getting (Maybe the gpu was having some problems, because of age?).
So I got the: NVIDIA Geforce GTX 760 (MSI), a new motherboard : ASRock B75 Pro3-M (CPUSocket), a new RAM: 8,00GB Dual-Channel DDR3 @ 665MHz and a new Hard Drive: 932GB Seagate ST1000DM003-1CH162 (SATA).
I kept my CPU: Intel Core i7 2600 @ 3.40GHz and my power supply: corsair cx750.

Since I have been using this build, my computer kept these problems and it has become even worse after 1-2 months. My league of legends started having really bad problems with having major fps drops to the 0-30 fps, sometimes it froze for a couple of seconds. I have been checking my temp for so far, because it's getting pretty warm in my room, but it never has been to a dangerous lvl and it got checked by some of my friends that have some knowledge about it, the highest my CPU got was about 60 degrees. I have tried to reinstall the client, but nothing helped.

I started playing World of warcraft aswell since a week ago and it was impossible for me to play. Fps keeps dropping from the 95 to 0-20. I noticed though when someone lvled up or someone joined somehow that's the point where it freezes.

I reupdated my drivers from my cpu, gpu, motherboard, etc. I have run benchmarks what seems to be completely fine and it ran smoothly. Since I got my new upgrades I did get Windows 8.1 Pro 64-bit.
And I have been running tests that burden my computer.

Is it possible my CPU is dying? (I already got it for around 3-4 years)
Somebody on an other forum told me to post this problem here, because maybe it's a driver/software problem?
http://linustechtips.com/main/topic/174517-major-fps-drops-while-playing-games/

Programs I have open while playing games: imgur: the simple image sharer

Thank you for reading

Could be overheating or software issue. CPUs don't just die. On rare occasions with a heavy OC maybe. But modern CPUs as long as they are properly cooled will last. In fact a silicons chip lifespan is hundreds of years, OCing it would reduce it by what maybe 50%? By the time it dies it will already be obsolete.

What level are you setting the graphics card at? Have you tried the lowest settings in all games? See what average FPS you get there. I doubt your CPU is to blame as you would suffer multiple BSODs and other issues from that. I know that the 6 series is still ok graphic wise, but they are a little old now.

When you re-installed your graphics drivers did you completely remove the old ones first? What graphics card did you have before? Was its drivers completely removed before you installed this one? As I have had issues from a random set of old drivers buried deep inside my C:\ one before.