Extraordinarily Slow Render Times on FCPX 10.6 on 2019 MacBook Pro 16"

Greetings.

I'm an amateur/hobbyist/beginner trying to use FCPX 10.6 to do some basic edits. I've got a 16" MacBook Pro from late 2019 with an 8-core Intel I9 (2.4 GHz base speed). When purchase, it was the most maxed-out model you could buy (64 GB RAM, AMD Radeon Pro 5500M 8 GB, 8TB SSD Drive).

Currently it has the latest software updates (macOS Monterey 12.0.1) and, as mentioned, FCPX 10.6.

The file I'm trying to edit was recorded by a TiVo off of broadcast TV over 10 years ago (a local program featuring a friend) that was recorded to DVD using the TiVo. I ripped the video using MakeMKV. The command-line program ffprobe (part of the ffmpeg software package) indicates that file's one video stream is:


Since you can't edit this with FCPX, I used ffmpeg to to transcode it to ProRes 422 using the command:

This created a video file that ffprobe reports as:

I imported this into a new FCPX event in a new library. Initially, I had the default FCPX settings (had "Background render" on) and I originally elected to "Create optimized media" on import (even though the imported media already was ProRes... I didn't know if ffmpeg's encoding would be as "efficient").

Anyhow, I watched the status of the background encoding of the proxy file. It stayed at 0% for hours. So, I cancelled it and decided to just try editing without a proxy file.

The only edits I was making was to cut out commercial breaks and trim the program to just the part involving my friend. That's it.

So, what's my complaint? I did NOT expect my still-fairly-recent system to perform to poorly while trying to edit a 40 minute 720x480 29.97 fps ProRes file.

Specifically, the rendered timeline (specifically the audio waveform) wouldn't update if I scrolled beyond what was initially visible. Also, if I "played" the file for a while (spacebar/L) and then paused (spacebar/K) and then tried to resume (spacebar/L) I'd get the beachball icon and it'd take 30-90 seconds to resume playing the video.

Anyhow, I decided I ought to just bite the bullet and render a proxy to see if that'd make my editing process smoother. Perhaps the ffmpeg version of ProRes did something really weird. I also didn't want it re-rendering stuff every time I cut out a section, so I turned of "Background render", selected my original imported clip and requested that FCPX transcode a "ProRes Proxy" and went full-hog-minimalist so selected 25% frame size (yeah, of an already 720x480 file).

It took 5 days—FIVE DAYS—to render the proxy!

I used Amphetamine to keep my MacBook Pro awake and only minimally used by computer. It started on a Sunday and finally finished on a Friday morning.

Is this normal? This seems VERY odd to me. I mean, I can transcode the same file using ffmpeg to 25% of the original frame size (180x120, which is what the finally-finished proxy file is) it only took 4 minutes 40 seconds as opposed to over 5 days.

Also, FCPX was hardly using my system's resources when rendering the proxy file. I watched CPU and memory usage and it was almost always minimal. I kept FCPX as the foreground process. I kept the mac awake. The machine didn't even really get warm (and the fans never turned on). Anyone know why?

Anyhow, all that and it didn't even help. My editing process is still crap (the play/pause/play action still causes my machine to hang for some weird reason. As a software engineer who has some idea of video formats and issues decoding them, it is incomprehensible given my machine's specs.

Now I've finished the edit and I'm "exporting" the file (command-E; "File -> Share -> Export File - No transcode (default)"). This is on schedule to take on the order of 36 hours (it's only 2/3rds done now).

Because I was concerned, I ran a full system test on my machine after the proxy finished rendering and before I started this export/render. No issues. All other software behaves normally.

Anyone have any thoughts, insights, suggestions, theories?

Thanks.

Many users are reporting poor performance in 10.6.

zettabyte wrote:

16" MacBook Pro from late 2019 with an 8-core Intel I9 (2.4 GHz base speed). When purchase, it was the most maxed-out model you could buy (64 GB RAM, AMD Radeon Pro 5500M 8 GB, 8TB SSD Drive)....macOS Monterey 12.0.1)...FCPX 10.6.... I used ffmpeg to to transcode it to ProRes 422...I imported this into a new FCPX event in a new library....The only edits I was making was to cut out commercial breaks and trim the program to just the part involving my friend. That's it....I did NOT expect my still-fairly-recent system to perform to poorly while trying to edit a 40 minute 720x480 29.97 fps ProRes file...the rendered timeline (specifically the audio waveform) wouldn't update if I scrolled beyond what was initially visible. Also, if I "played" the file for a while (spacebar/L) and then paused (spacebar/K) and then tried to resume (spacebar/L) I'd get the beachball icon and it'd take 30-90 seconds to resume playing the video....Anyone have any thoughts, insights, suggestions, theories?...

If you only want to trim the file and cut out sections, you don't even need FCP for that. Quicktime Player can do that without re-encoding and should be very fast. See MacMost "Easily Trimming Video Files With Quicktime Player": 

However FCP shouldn't behave that way. If the file is somehow internally damaged due to the various transcoding it's theoretically possible it could trigger some anomalous behavior.

If you can use the above Quicktime method to trim out a smaller section which still reproduces the problem in FCP 10.6, then upload it to DropBox or some other place, I can test it on several different machines (inc'l a similar 2019 MBP 16), various versions of FCP, also Premiere and Resolve Studio.