Operating system: Arch Linux
Graphics card: GTX1060 6G
CPU: AMD Ryzen 5 2600
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen) Blender 2.8 RC1
Worked: (optional) 2.79
Short description of error
CPU and GPU hybrid rendering on cycles is way slower than just rendering with GPU. And when I try to stop the rendering, it takes forever and sometimes would just freeze.
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).