Playback is fine, render dips immediately to 0

I'm on Davinci Resolve 17.6. I have a 4k timeline with a bunch of greenscreen work and fusion effects. Footage is BMraw. Playback is a steady 25fps, however when I try to render the footage the framerate immediately dips to 0 and stays there, Resolve becomes unresponsive until I force quit. Any help? I kinda want to deliver this project tonight. Seems to be independent of codec, encoder used. I'm rendering to 1920x1080.

Processor, drives, etc. are all idling at like 10% capacity.

Windows 10, Ryzen 3800xt, 3070 card, 64gigs of RAM.

Welp, updating to the latest Nvidia Studio Driver (even though I was on the second to last before that) did the trick.

Never mind, still hangs a minute in.

Problem occurs on rolled back driver as well (457.30). It occurs on a 1920x1080 timeline on a 1920x1080 project as well. Very weird.