Premier Pro CC 2018 playback is stuttering

First, if you don't understand the nature of long-GOP media, you need to learn about it ... and that drone is long-GOP media. The few actual frames (" I " frames) that are recorded are highly compressed compared to "standard" H.264 media, and they have many "frames" between that aren't an actual frame, those p & b frames are just a matrixed data-set of pixels that either have or will change from the last or next complete frame ... or both. One of the active forum members had some media from a drone they analyzed a bit back ... and the full complete I frames were up to 120 frames apart, there were partial I frames in between, around 30 frames apart, and everything else were p or b 'frames' of matrixed data sets.

The cameras have specialized chips to encode that specific format of that camera model to card fast. It's plain nasty stuff to edit on a rig even more powerful than yours, as it rags out the CPU/RAM subsystems just for playback, leaving very little in the way of resources for an NLE to run itself on.

This is why the GoPro folks had a section of the manual for their Studio software explaining why the camera produced media out of their cameras was not suited to major editing, and they recommended transcoding to their Cineform codec for any "real" editing work.

I hope you have at least one extra drive in that, preferably an m.2 with a hot new Samsung SSD on it, to use for your projects/media. That would help.

Also ... this is why the PrPro team developed the proxy-on-ingestion process, which works quite well. Use the included Cineform presets for proxies (NOT the H.264 one!) ... drag the Proxy toggle switch onto your Program monitor controls from the control options for that panel ... and you'll find a much better experience.

Neil