R19.0 release : very poor Dynamic zoom performance

R19 release
OS 18.1 b3 or 4

TL is 4K 1.85 ratio 24.0, color managed

Dynamic zoom is having really poor playback performance. seemed to get worse on the release, maybe started in prev beta.

source is mix of iPhone 4K, 5K HEIC, single frame, nothing else added. Playback on simple scale and pan a bit is like .25 fps on a M1 Ultra with 48 GPU cores. I am driving a 5K studio display and 4k dell 27" if it matters.

res of image doesn't seem to change anything.

single layer of video is underneath for sound ( A roll video is underneath but never visible, 8K H265 720mbit lgop 422 ) . as a test I trimmed back video under 2 shots and it may of helped

Cache is set to smart, no red render bars in TL to R clearly thinks it can play this, and it should be.
Oddly the 8K h264 422 10bit 720mbit video with 2 node grades ( and input color space set to flog2) wants to be rendered which I also think is strange. it's nothing crazy going on and should just play. I can say for sure other apps are playing the same shots ok. Ok, since the aspect ratio doesn't quite fit I'm scaling the image to like 105% - is the problem the scaling code ? everything that seems to be doing some scaling is being slow ?

overall the playback of the release ver seems slow and boggy on hardware that should be way more than fast enough. I'm also seeing frames buffer up and then play out fast in some sort of catch up. It's all weird.

S

R19.0.1
OS 15.0 b7+

MUCH improved. some times RT 24fps, some times about 12 fps but way way better than before, I think iPhone HEIF's, just a single still with move, are still problematic. they seem to be the ones playing a. bit slower, but fuji 8K HIF's work ok playing sequences

We're now at DaVinci Resolve version 20 Beta 2, and HEIC still images STILL behave extremely poorly.