I have tried a number of things to get the laggy preview window from performing better. Though I have got it somewhat better the biggest issue is a transition between two videos, it gets really laggy there.
I am running a new MSI laptop with 16GB Ram Solid State Drive, GTX 1060 and I7
Things I have done
1. Changed the preview to half or quarter
2. Turn off GPU Acceleration (set it to none)
3. Disabled Resample Mode
4.SET enable multi stream render to true
These things have made it better but it always gets laggy between two video clips and though it is smoother during a video it still does lag from time to time where it freezes up, you can still hear the sound but the video has slowed down and needs to catch up
Frustrating... I have watched several YouTube videos n it and they all kinda say the same thing as above... I need more RAM? will that help