DaVinci Resolve 20 - Slow and unusable on NAS after update

So.. I upadted to davinci resolve 20 beta. Opened my previous project and to my supprise all playback is insanely slow. Taken off all grading, back to blackmagic raw. I'm editing across a 10gb ethernet on a nas like i always do, no problems but suddenly now it is so choppy that i can hardly even play back the raw file. Now i've updated the project so can't even revert to 19. Anyone had this problem?

Yes! And it's deeply frustrating. I create proxy footage of all my files using Blackmagic Proxy Generator and it's still stuttering through the footage, regardless of whether I have grading enabled. In 19 I could have edited the raw files on my machine with less difficulty. I'm using a local drive rather than a NAS. I'm afraid to open my larger projects and have them update.

I fear that they’re utilizing newer gpu models and that if our workstations are using older gpu it can be a problem. I’m on older Intel Macs with the Vega GPus (internal on the Mac and with the BMD eGPU) and wonder if that would be untested for and worse unsupported in the near future. I hope now.

What's strange is that DR isn't using a lot of GPU capacity, just 6%-15% (perhaps because I'm using proxies); my CPU is at 3% and my memory at 34% (with lots of other programs running), yet DR's performance is just absolute crap. It shows 7.5 fps in playback with grading disabled, four layers of proxy video and a wav audio file.

I'm not using a NAS but a complex Power Grade that runs at full speed under R19 runs at about 60% speed in R20.