Slow playback speed

Hi guys. I've talked with Resolve support and they are having engineering look into it after all of their ideas didn't work, but I also wanted to check here to see if anyone else had run into it or if anyone else had any ideas.

I've got Raw uncompressed 4.6k footage from the Ursa Mini 4.6k camera. We have about 10TB worth. Currently I've got it on a ThunderBay 4, connected via Thunderbolt to a Mac Pro, which has a Sonnet Twin 10G Ethernet adapter. This 10Gb ethernet is connected directly to a Windows 10 PC with a 10Gb adapter. I've tuned the network and I'm getting close to 10Gb speeds. Trying to play the media directly over the network in the Media Page, or even locally on the PC (on an NVMe SSD or even a RAM Disk), I get the framerate indicator turning red and jumps around between 14-24fps, with jerky playback.

If I enable smart cache, it runs fine once it's blue but that doesn't work on the Media page and I need to be able to easily play back all of the media so I can sort/organize/etc.

What we've tried:
- Changing around the GPU configuration to just use one GPU
- OpenCL vs CUDA
- Turning on Display GPU for compute
- Adjusting video bit depth
- Advanced setting for disabling GPU pinned host

I don't think the network has anything to do with it since the same issue happens when running locally on SSD or even a RAM disk.

PC Specs:
Asus Z10PE-D16 WS Motherboard
2x E5-Intel Xeon E5-2640 V4
2x 12GB Nvidia Titan XP (no SLI bridge)
256GB Memory