So ive looked through some other threads and wansnt able to find a fix for my problem. Thats why I decided to ask by myself.
The Problem: How is my CPU, a Ryzen 5 2600 overclocked to 4.2Ghz, rendering faster than my GPU, a RX590 overclocked to 1660mhz? Im using Blender 2.82. People told me that an RX590 would be about twice as fast as an r5 2600 but my cpu is like twice as fast as my GPU. Im also using "Auto Tile Size" which automatically calculates the best tile size for the current render device. Ive also heard that rendering on both devices at once may slow down the rendering and therefore tried removing the CPU / GPU from "OpenCL" but the CPU is still way faster than the GPU.