Slow Thumbnails, over 100% RAM usage opening bins/sequences

Hey there, 

I've been having this problem since I built my new PC 6 months ago but thought it was just how it is (until today).

When I open a project, Premiere freezes up while generating thumbnails on both the timeline and in bins. While it's happening RAM usage spikes to 100%+ (eats into pagefile) before calming back down after the thumbs are loaded. 

This can happen mid edit when zooming in and out on the timeline.

If my PC wasn't as powerful I would understand this may just be a hardware limitation, but I have the following specs:

CPU: Ryzen 9 3950x

Cooling: 360mm AIO

RAM: 64gb 3200MHz CL16 (2x32gb)

GPU: RTX 2070

Premiere/Boot Drive: Crucial P1 1tb

Editing Drive: Samsung 960 evo 500gb

Scratch Drive: Samsung 840 Evo 128gb

Today I had to use my old laptop in a pinch to quickly render something, and found that in the exact same project the thumbnail issue did not occur. The laptop is a i7 7700hq with 32gb ram and a 1070 mobile, so much weaker than my desktop. 

Outside of the weird thumbnail memory issues Premiere runs great on my workstation, just quite frustrating. I've tried tinkering with settings and updating/ reverting drivers and Prem versions to no avail. 

Any ideas? I'm editing 4k footage from a GH5