System Information
Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: Intel(R) UHD Graphics 600 Intel 4.5.0 - Build 24.20.100.6137

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Worked: (2.79)

Blendmode: Alpha Over will give a lower fps than Cross(gif):

On a lower spec computer or with a heavy video file change between Blendmode: Cross and Alpha Over.