Question pc underperforming

[rezaka16]

So recently I started getting less FPS in CSGO. I updated my graphic drivers, everything seemed to be fixed. Now it started again, I ran a benchmark on GTA V to see if the issue only occurs in CSGO or not, and I'm quite sure it's underperforming in GTA V too. On high settings in GTA V, it hit 100 fps, but at the last benchmark test, (the one where you're in a black vehicle) at the end it dropped to 49 FPS a bunch of times. I don't know what caused this, I don't think I've updated Windows or anything like that, and I don't know what to do.

 

[rgd1101]

full system spec? include brand and model of the psu