CPU or GPU?

As you can see from the list in my signature I don't have a bad computer setup. Not the fastest in the world either. I just installed the GPU because Davinci Resolve wouldn't even run with my previous GPU. It runs now but not as smoothly on playback of the timeline as I would like. My question is: should I get a faster CPU which might mean I need a new motherboard (I'm not much of a computer geek so I don't really know) or should I add another GPU to the one I just got? Would another matching GPU be much help? Getting a GPU with a lot more memory on it seems almost impossible right now; they just aren't available. Also, I don't have unlimited cash as this is just a hobby! Any good advice would be much appreciated. Thank you!!

What kind of files are you using?

Have you tried converting your files to a edit friendly format?

An edit friendly format is usually a large format, but buying more storage is cheap compared to a 2nd gpu/changing cpu&motherboard.

The files are 4K-30 MP4 shot on GoPro Hero8 Black. What format should I convert them to? I purchased a 2TB internal drive specifically for these files and have other hard drives giving me a total of more than 8TB. Storage shouldn’t be a problem. Any other advice would be appreciated. Thanks!!

Is the internal drive an SSD or a regular HDD?

Anyway, you can always select the clip and generate optimized media. Resolve will do it for you then.

Internal drive is SSD. I was just hoping to avoid generating optimized media. It seems like just one more extra step.