Mac OS high Sierra 10.13.4 NVIDIA GeForce GTX 780M 4096 МБ
Short description of error
Artifacts when render in Hybrid mode in version 2.8 and also the same issue in blender-2.79-cb6d7cb0b25 - see picture :
But in version 2.79.4 everything is ok:
Exact steps for others to reproduce the error
In settings activate GPU CUDA and CPU. In render settings activate GPU rendering. Render F12.