Timeline Lagging Even With Proxies

[Sami Succar]

I’ve noticed a big change in how Premiere handles proxies during editing.

In the past, no matter how many clips I had on the timeline—even thousands—once the proxies were attached, Premiere would fly through the timeline without any issues. It was smooth and fast.

Lately though, it feels like Premiere is struggling to load the proxies. As shown in the attached video, there's a noticeable lag when scrubbing or jumping through the timeline. Once the clips "load," performance goes back to normal, but that initial delay wasn’t there before.

The only way I’ve found to force the clips to load is to play the entire timeline at full speed a couple of times. But even then, the clips tend to “unload” again as soon as I start editing—making things choppy all over again.

Nothing has changed on my end—same machine, same workflows. It used to be a breeze once proxies were ready.

Has something changed in how Premiere handles proxies? Can someone explain what’s going on with this drop in performance?

Microsoft Windows 11 Pro, 10.0.22631 Build 22631
Intel(R) Core(TM) i9-10900X CPU @ 3.70GHz
ROG STRIX X299-E GAMING II
RAM 256 GB
NVIDIA GeForce RTX 3090
Samsung SSD 990 PRO 1TB
Samsung SSD 870 EVO 4TB
Adobe Premiere Pro Version 25.2.3 (Build 4)

[Dani_V.]

Hi @Sami Succar,

Thank you for submitting a bug report and sorry for the frustration. Would you be able to provide any more details on the source media and proxy format you are using? What kind of camera files are you working with?

Have you noticed if the proxies work well if they are on their own, with no source media attached? Additionally, is this visible only when scrubbing and jumping around, or is real-time playback affected as well?

Hope we can help you soon,
Dani

[R Neil Haugen]

What is the original media?

What proxy preset are you using?

How full are your drives?

Past that,  a six year old CPU is getting long in the tooth. Every major version of Premiere does assume newer, more capable hardware than the previous version. Which is totally to be expected in any software really.

And your CPU has no long-GOP capability, I'm not sure if that GPU does, and that might be an issue. 

Of course have you cleared all cache files on launch? 

[Sami Succar]

@R Neil Haugen

I’m definitely due for an upgrade. But the thing is, this drastic drop in performance happened almost overnight, which is why I’m treating it as a potential bug. My CPU and GPU didn’t suddenly age in the past month. This lag actually started showing up right before the latest Premiere update. I held off, hoping the next update would fix it, but unfortunately, the issue persisted.

@Dani_V.

I work with several camera formats, but my proxy workflow is almost always ProRes (Medium). Once a clip is “loaded” (not sure how else to describe it), playback and scrubbing are perfectly smooth. The issue is in that initial delay, where it takes about half a second or so before the clip becomes responsive. After that, everything behaves normally—until I start editing again and the lag returns.

PS. I’ve been using Premiere since before it was “Pro,” and I’ve always been a strong advocate for it. I just wanted to clarify that I don’t post bug reports lightly. I usually take the time to troubleshoot and rule out all the usual suspects on my own—I handle large projects and can’t afford to wait around for community replies. Most of the time I get things fixed myself, but this one really feels like a regression in performance.

Thanks again for taking the time to look into it, happy to provide any other details that might help.

[R Neil Haugen]

It showed up right before which update?

[Sami Succar]

Any ideas? This has really affected my usual turnaround time.

[Sami Succar]

Following up.

As you can see in the video below, this is a three hours timeline with 1684 clips. I have played it at maximum speed a couple of times to force all the clips to load. You can see how easily I can scrub through the timeline, it's pure magic.

As soon as I make a single edit, ripple trim in this case, and it's clear how laggy the timeline became. It's as though all the clips that fall after where the edit took place, were "unloaded".

This is really strange, as working with proxies in Premiere has always been such a breeze, and I'm still not sure what change caused this dramatic fall in performance.

[Dani_V.]

Thanks for that additional video @Sami Succar, the performance difference is very clear before and after the edit. A few more questions: What frame rate are your clips and do the proxy fps match the source fps? Do you know if there is any variable frame footage in there? Where is your media and cache stored (external hard drive, SSD, local disk, etc)? Do you see any processes occurring in the background or in the Progress Dashboard at the top?

I'd check and right-click in the Program monitor, and deselect 'High Quality Playback' if it happens to be selected. I'd also be interested to know if offlining the source media and just working with the proxies attached would show a performance difference—or another way to test: if you add all the proxy clips on their own (no full res media attached) into a separate sequence, are you seeing that same performance drop occur with an edit?

If you are interested, you could share your project and media (or at least enough media that the issue can be replicated with) and the team can take a look and investigate further. I can message you if you'd like to do so.

[Sami Succar]

Hi @Dani_V. , thank you for your reply.

Below is the clips info and their proxies, no variable frame footage, internal SSD, no processes are taking place.

Type: MPEG Movie
Image Size: 1920 x 1080
Frame Rate: 50.00
Video Codec Type: MP4/MOV H.264 10 bit 4:2:2

Proxy Media

Type: QuickTime Movie
Image Size: 960 x 540
Frame Rate: 50.00
Compressor = Apple ProRes 422 Proxy
Quality = Most (5.00)

And here's what I found after running a few tests following your suggestions.

High Quality Playback - already not checked.

Offlining the source media - wow, works like a charm, I can use this workaround and only relink the original before exporting for delivery.

Importing the proxies separately - works like a charm, no issues detected.

So the question remains, why is the original media affecting the performance when working with proxies? For me, this is a new issue, I haven't faced it before with the same workflow.

The material I'm working with is kinda sensitive, but I can share the whole project if it's only for internal review.

[Dani_V.]

Thank you for trying that out, and great that it can be a workaround for the time being. Sent you a message @Sami Succar.