Slow, choppy playback in Vegas Pro?

[GTechGeorge]

I currently use Sony Vegas Pro 16 for video editing as I enjoy making YouTube videos for fun. But despite my relatively powerful hardware, my general editing process in Vegas has been really sub-par from what I'd normally expect. My footage usually plays back at the proper 30fps I record in, but as soon as there's a cut in the footage or an image overlay, there's a very noticeable freeze to the playback, sometimes requiring multiple seconds to catch back up. Task Manager doesn't show my hardware being pinned at 100% or anything so I'm confused as to why this is happening.

 

Originally I was just considering a big CPU upgrade to a Ryzen 9 3900X or 3950X for the huge bump in cores & threads compared to my 6-core 12-thread Core i7-6850K. But I still wonder if that's even really the case, as the chip does just fine when I play system-intensive games.

 

I'm thinking it may be the fact that the video files are stored on my 4TB HDD and Vegas is constantly trying to access them from that drive instead of a much quicker SSD. Any thoughts?

 

My system & specs: https://pcpartpicker.com/b/qynH99