low perfomance after a restart

[Korzon]

I was playing and switching even every few minutes between 3 games, god of war, mercenaries and dbz bt3, in all I was doing excellent, at 60 stable with jerks that did not even last 2 seconds, I had the laptop on for a while, so I gave it a reboot and when I went back to play, inexplicably the FPS decreased by half or even less, I do not understand why. By the way, I have a corei5 5300u with the INTEL HD 5500 and 8 GB RAM and a 228GB SSD.