Phones? Captions? What's causing the appalling performance?

[POwens]

I'm working on a feature doc and all performance is horrendous - playback, interactivity, etc - it's a dreadful experience.   The job is normal, the hardware is perfectly capable of handling it, and has done so on both Avid and Premiere projects continouously for the past 3 years.   The 4k project contains pro camera dailies proxied to 1080 ProRes Proxy, and tons of phone footage, much but not all of which is proxied (separate thread alert).   The timeine is 1080 23.976fps and Previews are ProRes Proxy. I'm trying to figure out which is the most serious issue I need to address here:

- The entire movie is  non-english, so there's a features-worth of a single caption track.  (As an experiement, I converted that to a text layer and deleted the caption track, which did nothing to help the performance)

- very many phone videos (portrait and landscape), from probably every model phone known, all of which is VFR

- phone videos have a declared fps of every kind - 20, 23.976, 24, 25, 29.97, 30, 59.97, 60fps, and every possible frame size and phone audio format known

- multicam clips, some of which have a phone as B Cam

- timeline is fully rendered (ProRes Proxy 1080)

- macOS 12.6.1, PPv23

- Proxy mode is on, canvas 1/2

- I delete the Media Cache every few day - that helps a tiny bit

- crashes are failry frequent

- but it's still like dragging a fully-loaded dog sled over dry clay.  Typing a caption or text title is one...character....at...a....time, takes about 20 seconds to type out four words.

Shorter, new sequences in the same project perform very well.  The project (it's professionally set up as a Production) has gone through two other editors, and I'm the only one who has these issues.  I was convinced the worst issue is the phones I can't proxy (separate thread) but when they're in a fully rendered 1080 ProRes Proxy timeline, and it's still is like pulling treacle?

Where do I start?

[MarekMularczyk]

What are the specs of your machine?

[POwens]

BTW, something is off about that info panel (wonder if that's connected?) - this computer has the 5600M with 8Gb RAM GPU, with the HBM memory.

[POwens]

Update on this:  Things became so bad, I was literally unable to move around the timeline or have any kind of playback, even with a fully rendered timeline.   In desperation, I rented a Mac Studio 10/24 core, replaced the MBP and was able to work very well for the first two days.

But even on the Mac Studio, it was obvious some of the phone footage (proxied) caused choppy playback.   Today, the Mac Studio is struggling to play the timeline, and when I open a sub-project, it takes absolutely FOREVER for the "Media Pending" messages to disapper.   Moving around on the timeline is impossibly slow, and most actions, like typing a lower third, performs just as badly as on the MBP, one.....character.....at....a.....time.....zzzzzz.   Finally yesterday I endedu p tearing my hair out again as the Mac Studio shut down unexpectedly multiple times, and on one occasion - with only two projects opn - told me it had run out of memory, and I had to Force Quit (it has 32GB RAM, my MBP has 64).

PS  I never mentioned that all the media, and project is on an OWC Thunderbay 4-drive RAID