I've never sped up a clip by 25x, but I can take a stab at a potential bottleneck for your workflow!
You are asking the system to pull in (25x normal playback media transfer rate) and decompress (25x normal playback decompression) to play a non-rendered video track at 2500% speed. So, your drive speed as well as your CPU will have to work really hard to pull this off without pre-rendering your timeline.
I would expect my performance monitoring would show either cpu or disk reaching limits. My cpu doesn't go above 70% util. Disk im not exactly sure what to measure but my disk system is a Raid 0 array of 2 1tb Samsung evo ssds, which is probably a gb/s rw.
I'm going to try and unlock more memory tonight, this nvidia memory limitation bug is holding me back there.
Now using 56GB DDR4 RAM. Here's the basic Task Manager performance profile when playing a 5D MKII native clip for 36 seconds at 2500% speed.
It actually does look like the disk is getting hit pretty hard, but not sure that "disk active time" is considered a good measure for a bottleneck, however.
C drive is 2x1TB samsung evo drivers in RAID 0 via intel controller on the MB.
Here's the same clip on my D drive, which is a 3x2TB WD Black RAID 0 (windows disk manager raid). Clip still jitters in places (not smooth). Active time is much lower.
Agree, it doesn't look like you are drive I/O limited.
And, if you are CPU bound - why are you not seeing 95% or more CPU utilization?
If you share a sample project w/ media somewhere, I'll give it a go on my a dual 8-core Xeon with lots of drives and see how that works.
Finally, this may be rather obvious, but have you tried playback at full, 1/2, 1/4, 1/8th resolutions to see how that might impact things?
I'll PM you to give you a sample clip that exhibits this issue.
I have tried 1/4 res on this (APP won't go lower for this clip) and the issue is still there.
One thing I just noticed that will help mitigate this issue is this "Render and replace" option for clips. Is that a new feature? It's so helpful. It auto-creates DNxHD proxies that look great and don't exhibit this behavior. I haven't tried exporting yet, but I'm guessing it even auto-replaces those with the originals when you do your final media export.
Looks like "render and replace" can be reversed at the sequence-level. Nice - sorry I missed this feature earlier, seems like it's been around for a while and makes proxy generation and reversing back to native super easy: Adobe Premiere Pro Help | Render and replace media.
I ran your .MOV clip in a fresh project, put it on the timeline, and set the speed to 2500%. Observations below were largely the same (most unexpected by the way!) for 3 very different systems (listed below):
- Initial playback was dropping some frames, but didn't really look too bad; CPU is definitely working the hardest for this workflow
- After changing two rather random things, all 3 systems could play this back with zero lost frames. Settings included: Memory: set so 8GB is available outside of Premiere Pro (default is 3GB), Sequence Setting: checked Max Render Quality box (default is off), and performed a "Render Audio" on the sequence (this takes less than one second and seems to help a bit).
- Rather interestingly, this particular workflow actually seemed to work a bit better when MPE was set to software only (GPU off)
Systems tested included (all running CC 2014):
- 3 year old x58 6-cor i7-970 with SSD array, 24GB RAM, GTX 480
- 2x Xeon e5-2687w, 128GB RAM, GTX Titan, single Samsung 830 SSD for everything (OS/Programs/media/projects/swap/cache/scratch)
- 1x Xeon e5-2687w v2, 64GB RAM, SSD array, GTX Titan
- What version of Premiere Pro are you using?
- How many dropped frames are you getting when you just playback this clip?
- Have you ever tried doing just a small project with just this clip (at 2500%)?
Thanks Jim for taking a look at that.
Will test it tonight on my new system. RE: Audio: for sped up clips I don't use it so will unlink and remove. That leaves Max Render quality on (you'd think this would slow it down even more), and leaving more RAM avail outside Premiere (same thing, you'd think this would hurt perf).
Very strange, but will give it a shot.
Sorry, just saw your Qs as well.
- Using APP 8.1 (latest updates)
- Dropped frames: 20-30%+
- Small project: Yes, before I sent it to you. Sort of N/A, however, as I need to edit it in the context of my larger project.
I just tried what you did, no meaningful change. Agree what you did sounds random and I don't see how they would contribute to increased playback smoothness. I would expect the opposite.
Thanks for checking though, I think I'm happy with the Render and Replace option.
Have you turned write-cache buffer flushing off all of your drives and arrays?
Have you unchecked the "allow files on this drive to have contents indexed in addition to file properties" boxes for all drives and arrays?
If not, both of these settings help drive performance, which seems to be the critical path in this case.
I thought people stopped the buffer flushing thing.