Question PC performs much worse than before

[MrrSpeaker]

I had issues with bluescreens and various error codes not too long ago that got fixed by updating my bios. I also used a tool to remove and and reinstall all graphic drivers because of a GPU issue I had right after. Now, after using my PC for a while after fixing these issue, I'm noticing a pretty significant decrease in performance from my fairly high end PC. Not sure where to start looking for the problem. I've run benchmarks, though they tell me the performance is average for the components I've got.

Specs:

GPU NVIDIA GeForce RTX 4070 Ti (MSI)
CPU: Intel Core i9 9900K @3.60GHz Coffee Lake
Motherboard: ASUS ROG STRIX Z390-F Gaming (LGA1151)
RAM: 4 sticks AKA 32GB G.Skill Trident Z RGB 3200MHz
OS: Windows 10:
Storage: Kingston SA2000M81000G 1TB M.2 SSD (for OS)
KINGSTON SFYRD2000G 2TB M.2 SSD
Corsair Force LE SSD 250GB
Seagate ST8000DM004-2U9188 8TB HDD
Seagate ST2000DM001-1CH164 2TB HDD

 

[geofelt]

What kind of performance has decreased?
How are you measuring it?

 

[MrrSpeaker]

What kind of performance has decreased?
How are you measuring it?

Ingame FPS, frames missed due to rendering lag in OBS and CPU usage when performing actions and processes compared to, for example, 1-2 months ago.