I only know that it's 800W 80+ Gold. I'm not really that good with computers and mostly rely on my friend.Which power supply do you use exactly? With these components, a Seasonic PX 750 or 850 would be my recommendation.
Power supplies with inferior quality often have difficulties with fast and strong load changes. A simple 800W-Label isn´t enough.
I called the store where I got this rig from and they'll take it in since it still has a warranty and guy from the store, my friend and I all think that the PSU doesn't work properly. It works well when I'm just using the internet but at higher power needs, it fails.
But once again, a big thank you to all of you for your help and tips! I learned a lot from them
It's also quite funny that I get a way more friendly and helpful attitude towards my problems here than I did at an actual tech forum where people were mostly calling me an idiot