How to fix choppy 4K playback?

On the edit timeline, it plays back choppy. So far I changed the proxy to quarter resolution and also tried the Retime and Scaling adjustment to Near and Fit. Are there any other ways? The delivered product plays back smoothly and it also seems like it plays back smoothly on the Deliver tab.

No one can help you without detailed system information, codec of the footage, what version of Resolve you're using and how you've set it up (timeline resolution, montoring resolution, etc).

Before you do that you might want to search the forum for posts which have reported the same issue -- there are many of them. You may find your answer among them.

Here are my specs:

Intel Core i7-4720HQ CPU @ 2.60GHz, 2594 Mhz, 4 Core, 8 logical processor
GeForce GTX 960M, Nvidia. 16GB Ram

Footage is MP4 4K @ 24fps using Resolve 14 version 14.0.0b.023
Timeline at 1920x1080 HD and monitoring at 1080p

Your system is weak even for HD, and the free version of Resolve is not well-suited to .mp4 editing generally, least of all 4K. You'd need the Studio version if you want good performance with h.264 material.

For now, check out "Optimized Media" in the manual or transcode the clips to DNxHR before you import them. You might also want to install the most recent beta.

Ah so it must be a combination of things. I'll try out your suggestions, thanks!