Question FPS problem - Bottleneck of the computer

[Garou]

My FPS is always very unreliable. Sometimes it goes to 220, and suddenly it goes to 80. It is on a regular basis very unsteady.

I have tried everything I could to adjust settings. I adjusted on nvidia panel(more performance), adjusted game settings to the lowest they can be, checked that my drivers are up to date. I also changed the priority of the games to the highest for the cpu. In control panel I changed power plan as "high performance".

I am beginning to wonder if my hardware is the problem.

Operating System
Windows 10 Home 64-bit
CPU
Intel Core i7 @ 4.30GHz
Kaby Lake 14nm Technology
RAM
16,0GB
Motherboard
ASUSTeK COMPUTER INC. ROG STRIX X299-XE GAMING (LGA 2066 R4)
%1 Chipset
Graphics
ROG PG278Q (2560x1440@144Hz)
3071MB NVIDIA GeForce GTX 1080 Ti (ASUStek Computer Inc) 54 °C
Storage
465GB Samsung SSD 860 EVO 500GB (SATA (SSD)) 36 °C
1863GB Seagate ST2000DM006-2DM164 (SATA ) 32 °C
Optical Drives
No optical disk drives detected
Audio
NVIDIA Virtual Audio Device (Wave Extensible) (WDM)

Do any of you see any "weak link" here?

 

[rgd1101]

make and model of the psu?
cpu/gpu temp during the game?
game on the ssd or the hdd?

 

[Garou]

make and model of the psu?
cpu/gpu temp during the game?
game on the ssd or the hdd?

Corsair RM850x 850W PSU. Thats all I found.

Normal temps under the game.

I have all my games on SSD.