Question CPU working below expectation

[mineccrafter444]

My CPU: Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz Base speed: 3.00 GHz

I use userbenchmark and it says that my CPU is performing way below expectations. only get 1-3% usage while idle and 60-70% in a game and i get bad fps in my games and i think this is the reason for it anyone know what could me causing it?

 

[NightHawkRMX]

Full system specs?

What are CPU and GPU temps in-game? Are you using the stock cooler?

 

[mineccrafter444]

using stock cooler temps are around 50 Celsius on each and specs are
CPU Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz Base speed: 3.00 GHz
GPU NVIDIA GeForce GTX 1080
RAM 16G DDR4
SSD KINGSTON 120G
HDD 1tb
Mb Asus prime H370M