Gtx 760 Micro freezes | Micro stutters after few hours of gaming

I am experiencing this problem for quite a while and in fact it is so weird that I was unable to replicate it. I will try to briefly describe it.

My system is
AMD FX 6300 3.5ghz turbo 3.8ghz.
Gtx 760 ASUS 2gb in a 16X PCI-e 2.0 slot.
2x4Gb 1600mhz DDR3 kingstom hyper memory
Gigabyte 970A D3 REV 3.0 motherboard.
VS 650W Power Supply
CPU temps never exceed 40C
GPU temps never exceed 70C.
Using latest drivers.

The system is not overclocked. Everything is running at optimal settings.

Each time I play a game for a longer period, two or one hour or so It starts lagging and stuttering. I have these annoying micro-freezes each time I walk a few meters. The frames are solid when I stand, or move around a certain area. Lets take Alien Isolation as an example since I play it now. It would be a great example.

I am getting perfect frames, around 80 frames average. After 2 hours of gameplay terrible stutters start to occur. For instance each time I open doors the game freezes for 1 second and then frames jump back to the said 80. I think it happens because new section of the map starts loading, but I fail to understand why it starts "Stuttering" after a certain amount of time and does not happen for the first time the game is launched. After I turn off the game and launch it again the problem "MAGICALLY" goes away and the stutters reoccur after the said time.

Of course this is not the only game I have noticed to have this problem with. It happened with Watch_Dogs and Dead Rising 3. First I was blaming the optimization, but now when I see that the same "symptoms" appear with other games as well, I started blaming my system.

I would greatly appreciate if you could tell me what is causing this problem and how could I fix it.


Thank you.

Accuracy, what are the temps for your GPU. Monitor tem while gaming