Inconsistent performance on High end PC

[oliver.elgersma]

I always try to fix my issues myself before going to forums, however this problem has me completely stumped.
I built my PC last month and I’ve been having extremely inconsistent performance on it since, which I wasn’t worried about at first because there were many things that could have been the issue, but now I am. After many stress tests, decent looking benchmarks, driver updates and optimizations to control panels, I’m not sure what’s causing this issue.
Basically I have some great days, where my PC is performing optimally (200+ FPS) in most games, then the next day I’m micro stuttering and struggling to get 30fps. I feel like i’ve done everything, and even tried over clocking to see any differences (reverted the OC due to instability) but nothing.

If you have any suggestions PLEASE help because my next resort is a repair shop.

Specs:
ASUS Z370-E
GTX 1080ti STRIX
Intel i7-8700k
G.Skill Trident Z RGB 16gb
Samsung 970 evo 500gb

 

[Dugimodo]

If it happens randomly maybe it's something running in the background hogging resources. Have you tried monitoring CP/GPU/Memory usage while gaming to see what's different? MSI afterburner has an option to overlay these on the screen.

If for example the CPU is mysteriously running at a higher % sometimes you could alt tab and check task manager to see what's using it.

 

[dontlistentome]

Well, I'd start with suspecting power issues. A defective power supply might be the source of intermittent issues. I notice you list all your components except the power supply, which leads me to think you don't know how important a good power supply is, which leads me to think you might have bought a cheap one.

The other thing I'd like to know is specifics about what's going on. "Most games" doesn't say much. Some games have their own issues, some don't.

If you have two sticks of memory, try using one stick. It will impact performance, maybe depending on what you run, but the idea is to see if performance stays consistent no matter at what level. Then try it with the other stick.

Finally, I'd run MSI Afterburner at the same time I run games. I'd want to see if there is any difference in CPU/GPU usage, temps, speed. etc between when it's running with good performance and when it's running slow.