Sluggish timeline performance when "Show duplicate frame markers" is enabled.

BRINGING THIS UP AGAIN - should be noted that while this (sluggish performance when Show Duplicate Frames is on with more complex sequences) WAS fixed from 24.1-on - this same exact issue has RETURNED in 24.5.  Have not tried 24.6 Beta yet, but for sure seeing it again now that I've gone to 24.5 when I wasn't thinking it was an issue anymore.

I also see this issue on 23.6.2 (Windows). Very clear sluggishness with dupe frame on, goes away with it off. So I have to turn it on when I need it which is a real pain.

I hope it has been fixed on the 24.2 main release coming out now.

(Seemingly) Good News, Everyone!  I opened a problematic sequence in my current version (haven't updated fully yet, so still at 23.6.2) and while (as I previously posted) it did NOT work in that version or 24.1Beta, it IS seemingly FIXED in the recently updated 24.2Beta.  (Note - I have not tried testing in official 24.1 release, so I can't speak to that.)

So yes, opened bad sequence, works fine without "Show Duplicate Frames" on...and now no apparent UI speed difference with that turned on in 24.2Beta. 

Progress! 

It's incredible that this issue has not been resolved. It has been a known problem for so long and to me it suggests a fundmental problem in the build and design of the gui for the sequence interface. Having a sluggish timeline is not condusive to editing.

I also experienced this problem, again, in PP 23.6.2 on a Mac Mini M2 Pro (32 GB RAM). As everyone above has mentioned, turning off "Duplicate Frames" solves most of the lag and sluggishness of moving through the timeline. I recall this also being an issue years ago, and I found a thread on Creative Cow dating back to 2014 that had the same temporary solve for this: Creative Cow - Lag and Sluggishness with Complex Timelines .

I have the same problem here. Once I enable "Show duplicate frame markers", the responsiveness drops to near zero, making it nearly impossible to work, even with simple timelines. I've been facing this issue for many versions, and only recently, I discovered that disabling that feature restores smooth functionality. I thought that my computer was getting old, but it's definitely a software problem. It's a pity because as editors we needed it. I hope Adobe addresses this issue soon because I've noticed that the UI feels slower compared to other NLE like Resolve, and it doesn't seem to be improving. What a shame.

@Stan Jones 

I've had same EXACT issue, for several versions.  Thought it was just my system (2017 iMac Pro, 64GB Ram, OS 12.7.)

BUT, I opened a timeline that is complex that was acting poorly in 23.6.0 in the 24.1 Beta and it was working well. 

THEN I changed the same "Show Duplicate Frame Markers" and blam, sluggishness returned.  In other words, no difference between 23.6 and 24.1Beta with this issue.

So a couple tests:

--sequence had one track of video and 6 tracks audio (see below).  No effects, this was a selects reel with NO duplicate frames.

--Not just zooming, but entire interface slows to an absolute crawl. Even just clicking on any button, play, stop, or renaming a sequence...everything painfully slow scross the board within Premiere's UI, beach ball spin for a second or two for any key press or click...IF a complex cut is zoomed out.  Once zoomed in, all good.  Or turn the setting off, all good if zoomed in or out.

**Deleted one entire track of audio at a time, no change. BUT, when ALL audio was deleted, interface sped up a lot.  I tried duplicating the video track many times on higher video tracks and it got slower, but not NEARLY as slow as with even one track of audio (I've tried with and w/o waveforms).  About 65% interface speed.  When setting turned off, 100% speed again.

Hope this helps, I'm glad it came up that there's a workaround (I thought it was just 'complex cuts suck on your system, so there', but great if figured out for future.

As an example...

@Stan Jones 

Thank you for the reply.

I tried your suggestions, both disabling tracks and deleting the clips at the end of the timeline after the gap, no difference. Turning of Duplicate Frame Markers seems to be the only thing that works right now, which is fine for the time being. But it is a feature that helps a lot, I hope this problem will disappear for me in future versions.

Thanks for submitting; a very good demonstration of the problem. I have not been able to replicate it. I tried some time ago, because turning duplicate frames off helped sluggish work with caption tracks for some users.

Your timeline is relatively complex. If you simply disable (eyeball off) one track at a time, can you tell whether it is certain tracks that contribute? I assume no, since the duplicate clips are in multiple tracks and spread throughout the project.

Does it matter if you delete the material after the gap?

I'd "save a copy" of the project and work in that as a test.

Stan