Crashes and choppy despite 24fps playback rate

Hello,
I'm using Resolve 15 b2 - Experiencing choppy playback and crashes. This happened in Resolve 15 b1 as well.
My setup is i7 3.6Ghz, 16gb Ram, AMD RX480 Resolve + Media on a 400mb/s SSD with 800gb free space.
Resolve shows 24fps playback rate (green) yet it's choppy as hell.
I'm using Optimized media (DNxHD low quality) on the SSD as well, + proxy half resolution of 4K footage, 8 bit, not raw.

Other than the choppy playback, I get constant crashes, and they are weird.
It happens during playback and it changes my deskop resolution to 800x600. It says Memory could not be written.
I also have crashes where the pc just freezes and I must restart
Final type of crash is simply when the program quits, no error message, usually when I click from the Timeline on the Color icon, to go to the color pane.

My computer is not a beast but it should be able to handle 4K optimized media, at half resolution... It was Okay in Resolve 14 (a few crashes here and there with a lot of OFX, that's it)

Anyone experience this? Thanks in advance for suggestions or assistance

[Peter Chamberlain]

Please review for log info
viewtopic.php?f=32&t=71894

Here are the logs: https://we.tl/sHcH5kxchD

Just had another crash - very weird, my computer would do beep sounds whenever I would move the mouse! Had to restart the computer.

Steps to reproduce:
Open Resolve 15
Click on Color tab
CRASH

Here are the logs after this crash: https://we.tl/bO0JsNzeB7