Major premiere pro lagging issue!

your 1st problem is you got the KF version of the intel CPU which is a No-No for us video editors.. as far as Intel CPUs goes you need to get the K version not the KF. That is why you are using 100% of your CPU your next problem is you need to check and see if you are running on Cuda cores. To see if you are  go to file project settings> General > video rendering playback> and make sure that setting is on Mercury playback  engine GPU acceleration Cuda cores,  and that should solve your problem if you still have any issues I suggest you start using proxy files..

Hey, hey, Justin. What's up?

Nice rig! Congrats. Have you tried the normal NLE troubleshooting steps, like, closing all projects then emptying media cache in Preferences > Media Cache? That can help. Trashing preferences can also help. Placing media cache and source media on SSD drives other than your C drive? That helps. Trying a new project with fresh media can also be a test you can try. Have you lowered any of the resolution settings in the Program Monitor, you can edit in 1/8, yes? You can also switch off "High Quality" in the Settings (spanner/wrench) menu. 

If you've tried these things, this may be a case of cutting edge formats being too heavy for their own good and even the best computers being a little too far behind the technology curve compared to these "new wave" formats.

My assumption is that you've got 4K 10-bit 4:2:2 HEVC footage that you're working with. You've also got to add an input LUT because you're shooting log. This all adds up to "no computer on earth can play this source footage back smoothly in Premiere Pro." May be overstating that a bit, but trust me, this footage is very highly compressed and requires a lot of CPU/GPU power. 

If it were me, and if this is what you're finding, as well - I'd set up a custom ingest preset with the input LUT included. I would set up to ingest the footage in some flavor of ProRes, DNx, or GoPro Cineform. That way, you could continue to edit 4:2:2 10-bit with a visually lossless editing codec with the added ability to edit clips in a higher performance environment and access to smart rendering.

I think you could also use the proxy workflow, but you'd have to set up some custom proxy presets for that, as well.

If transcoding is a good solution for you, stock up on hard drives because these files are quite large. Good news, though. You merely discard them after you output as they are really only for editing purposes. You can always create these files once more from your originals, if needed. Proxies will also require added storage space, just not quite as much.

Hope the advice provides a solution for you.

Thank You,
Kevin