I have an RX 580 paired with an i3-8100 and 8GB of RAM and my GPU is allways doing this and it is very bad for my FPS.
The GPU usage is going from 100% down to like 20% and up again, very unstable and the fps goes with it.please be more specific about what your gpu is doing exactly.
It happens when i play games, my PSU is a Corsair VS550. It didn't use to be like this.Which POWER SUPPLY unit are using to power up this GPU ? When does the GPU does this, while playing Games ? What's the GPU usage and load when you play games ?
List the make and model of your PSU.