Question Why do I see a big performance drop?

[ST0RMR4IDER]

Hi, I've built a pc some time ago and since then I've seen a huge performance drop. For example in Rainbow Six Siege my frames dropped from 250+ to 100-120. Plus ive been getting a considerable input lag overall. The gpu usage is constantly below 50%.The games are located on an SSD and I've tries resetting the whole system and reinstalling windows through bios.

Specs:
Ryzen 7 2700x
RTX 2080 Gaming X trio
Corsair DDR4 3200mhz 16GB
Corsair 750Watt PSU

 

[Grobe]

Did you upgraded some software or driver prior to this performance drop.

 

[ST0RMR4IDER]

Did you upgraded some software or driver prior to this performance drop.

Well of course but i reinstalled all the drivers completely several times.