Issues editing large/long h.264 files (multiple smaller h.264 files are fine however)

[Wesley S.]

When editing large (upwards of 10gb) h.264 files premiere often stutters and freezes.  Premiere never fully crashes, but it's bad enough that I cannot continue working.  This does not happen with shorter videos, even if they are of a higher resolution.  I can't stress enough that this is only an issues with low-ish resolution h.264.  It doesn't happen with REDcode RAW, Blackmagic RAW, ProRes or any other format.

My pc: 

CPU: 3950x

RAM: 32gb @3200mhz

GPU0: RTX 2080ti

GPU1: GTX 1060

Storage bandwidth is not the issue

I have tried with only the 2080ti installed, as I know that Premiere has had issues with multi-GPU in the past.  Both cards are running the latest Studio Driver from NVIDIA.

Any help would be greatly appreciated as this is severely impeding my work.

[gerikp · Accepted solution]

Whenever I encounter problems like that I transcode my footage to a mezzanine like ProRes 422. This always takes the strain off of Premiere Pro having to deal with a Long GOP h264 compressed file. 

[Wesley S.]

I understand this - but due to the length of the footage this would leave me with almost 15 terrabytes of storage requirement.

[basil1891]

Could be some sort of a memory/buffer management bug. I'd try to switch priority from 'performance' to 'memory'. Or try to borrow additional 32GB RAM and test. Since you have 16c/32t CPU, more RAM is actually recommended: https://videoguys.com/blogs/news-and-sales/avoiding-ram-starvation-getting-optimum-performance-in-pr...
Another option is to run the file in question through my 'vfr-to-cfr' tool from this package: https://1drv.ms/u/s!Andr88T403SpgRL5G8nDA5pXK_Vf?e=dwpceJ
Even if you pass CFR-file as input, it still checks for errors in fps metadata, so may help still. It works with a file copy, the source remains unchanged.

[Wesley S.]

So thanks everyone here who tried to help my idiot ass - I've figured it out.  Here's my solution for anyone having issues of their own:

I couldn't figure out why, when I had the video file in my selects timeline, it was fine, but as soon as I took it to the master sequence, everything stopped working.  I did a little bit of thinking (something I'm not too good at) and realized that I had applied a scale effect to the footage in my main sequence.  With it removed, everything played back fine.  In the end, I transcoded all of my footage so that it was the same size, negating the need for said effect.  The issue is not present with any other effects (lumetri color, RG Universe, time remapping, etc.)

TL;DR - motion effects (scale, position, etc.) were the issue.  Transcode footage to all be the same size.  No other effects cause the issue.

I would encorage adobe to figure out why this one effect is causing such a huge performance cost.

[Andy 1968]

If your sequence is set to show continues thumbnails for each frame that is to be expected. Your CPU has to work hard to redraw or refresh the individual thumbsized frames when using H.264 as opposed to Pro Res or R3D files.

[Christian.Z]

1- Storage bandwidth CAN be an issue, please provide us with your storage configuratgion, and where are you storing everything related to your project.

2- Resolution does not have a role on the "heaviness" of h.264 files. Bit rate does. Especially if its variable. Please share some more detailed info about the files.

3- Proxies are your best friend, no matter the codec, no matter the performance of your system.

4- Larger files tend to take longer the conform. Make sure you are giving enaugh time for the conforming to finish

[Andy 1968]

The video below might help demonstrate what Premiere Pro is doing under the hood.

[Wesley S.]

1. The footage is stored on a solid state SAN.  I cannot provide a lot of config details, but I know that the storage is capable of random read/writes at up to ~8gbps.

2. ~4002 kbps

3. storage size  is an issue, and while I do understand the usefulness of proxies, transcoding this footage is limited by the amount of storage I have

4. I always let premiere confrom 100% of the files before I start working on the project.

[Wesley S.]

*1 the project file and scratch disks are local, on an 8tb m.2 raid config

[basil1891]

@Wesley S. In case you still looking for a solution, check this info, looks like it may help: 

https://www.reddit.com/r/premiere/comments/md2qwo/weird_trick_that_fixes_mp4h264_files_stuttering/