Rx 580 does not create the simplest games in some cases?

Sometimes, with my rx580, every game starts jerking, even in fortnite then only 20 fps. I did not have such problems with my GTX 960 before.

Actually, the drivers are installed, so how can I fix it?

And the GPU is the only part that is installed in your PC? One of these GPU Only PCs without motherboard, processor and co?

Otherwise I have a top pc with i7, 16gb ramm and co.

like I said my gtx 960 ran better with 2gb in the same pc

Not too weak!

Where did you buy the video card? Could be a fake card.

If it is new from eg Mindfactory then check if you have the newest drivers.

If it is needed from eBay or from Amazon / Wish / Juke or so then send a picture of the map.

Have you purchased new from Mindfactory and the latest drivers should also be installed.

Can you tell me what you have for a power supply then?

What kind of power supply?

Bequiet SytemPower 7 with 400Watt, which should actually be enough.

Bequiet System Power 7

That's true

Hm okay sorry because I really can't help you, contact Mindfactory you can vllt send them back or get a new one