Resolve pauses at beginning of every clip while rendering

Hey guys, I'm trying to render individual clips for a grading round trip to Premiere, but when I start the render, Davinci stops at the beginning of every clip for about 1-2 minutes, then renders the clip out at basically realtime. the problem is it hangs on each clip for so long it times out and I get dropped frames. The clips are UHD ProRes from a UMP, and I'm running Resolve 14.3. My specs are as follows:

AMD FX8350
32GB G.Skill Ares RAM
GeForce GTX670 Superclocked+
Sandisk Extreme Pro 480GB SSD
Windows 7 Pro

I don't have anything else running in the background, and this is after a fresh reboot. I'm using the standard Premiere XML settings, so the export format is QuickTime Uncompressed RGB 10-bit. I've tried using OpenCL and CUDA, no difference. Any thoughts?

Oops, made a couple changes on the specs. Should be correct now.

Okay, I did some more tests, with different rendering codecs. Here's what happened:

Uncompressed RGB 8-bit, UHD: Rendered slightly faster, but still got stuck at each clip
Uncompressed RGB 8-bit, 1080p: Rendered faster than realtime, still got stuck
TIFF RGB 8 bit, 1080p: Rendered approximately 8fps, but doesn't seem to be getting stuck
TIFF RBG 8 bit, UHD: So far it renders about 1-2fps, but it isn't getting stuck
DNxHR 444 10-bit UHD: Renders at 10-11fps, gets stuck but only for about 10 seconds on each.

So it looks like the problem is codec-dependent, with each one affecting the render differently. I'm thinking maybe it's just more than my old system can handle these days.

For resolve and uhd, that system seems underpowered.