FPS lagg ~ not the usual one

Borjah

Ok here is the thing: when in-game every ~1 min my screen freezes for half a second as if I was taking a screenshot, the rest of the time my fps are above 200.

My-specs
cpu i7 4790 @ 3.6Ghz
nVidia GTX 660 2 GB
8GB of ram

Any help will be much appreciated

]Sake

This happens to me too, but only for the first 15 minutes of playing. If it ceases to happen after a certain amount of time passed, it is most probably your computer.