Turning Off the optimisation also fixed my playback problems. Before I could not play a single HD .mxf clip, now I can play 10 4K clips at once. No more transcoding.

The "Threaded Optimization - Off" solution is working for me too. Thank you so much!

@One Love
Awesome find!
I found many other instances of the Nvidia Threaded Optimization setting causing the same stuttering too, such as:

https://devtalk.nvidia.com/default/topic/780465/opengl/nvidia-driver-threaded-optimization-/

https://www.avsim.com/forums/topic/500955-important-turn-threaded-optimization-off-in-nvidia-control-panel/

I have a Threadripper 2950x and was having issues with dropped frames on Sony XAVC-L HD files and by turning the setting "Threaded Optimization" to OFF in the Nvidia Control Panel seemed to have solved my issues. You'll need to restart Premiere after changing the Nvidia settings to have it take effect. Hope this workaround helps someone.

It's been over two years since Threadripper released, and over one year since Adobe tuned into these issues and said they are investigating.

What has come from this investigation so far? Nothing. All of us with a Threadripper and Nvidia GPU combination seem to be screwed indefinitely by this problem.

Oh well. Adobe, if you ever look at this though, send my email a message. I'd be happy to provide you with samples of the issue, and help you troubleshoot. It's embarrassing how long we've all waited.

as of version 13.1.5 this is still a regular issue for me.

They seem to be still "investigating", since more than a year ago. I guess the half an hour they allocated for it has not been enough, especially because it coincided with the coffee break.

Meanwhile, they release useless effects and invisible improvements to Premiere, but nothing ever happens to bugs reported and features requested (mostly by professional users, I might add) here. This "Uservoice" is just a sham.

Anyone heard any updates on this?

Im getting drop frames playing back proxies nested in a multi cam sequence. GH5 and BMCC 4k proxied to cineform lowset default res, 1024x576 i think it is.

Any updates tho? I run a 1920x and 2080ti with 32gb of ram and SSD's.. Running back 5K R3D footage in 1/4 or 1/8 to make it KINDOF stop lagging.. I didn't upgrade my pc so I could have the same lag as the old one.. come on...

I suspect that the 3000 series CPUs will see a whole bunch more people jumping up and down on this thread. Me too quite probably. And if I caant get it to work well that might be all the push i need to move to resolve.

Any update on this? I have a Threadripper 2950X with 64GB RAM, m.2 x 2, RTX 2080 ti. Recently it started struggling to playback. I have tried everything I know to try.

For people owning a threadripper and wanting faster conforming:
https://adobe-video.uservoice.com/forums/911233-premiere-pro/suggestions/37520083-multithreaded-conforming

AMD GPUs are unfortunately not an option for those of us who rely on CUDA, but older (!) Nvidia cards also work fine. Older AMD CPUs and Intel CPUs in general also work fine with the same new Nvidia cards

The frustrating thing is, the stuttering is clearly a software issue between a CPU and GPU that are both pretty much overpowered for most regular editing workloads - something to do in the way Premiere interacts with the Nvidia drivers for newer Nvidia cards, because it can and does work flawlessly when properly "prodded".

All Premiere needs to do is detect this particular hardware combination and engage whatever it is that gets triggered by temporarily lowering the number of cores...

PLEASE READ THIS!!

I had the exact same issues using my 1950x with a GTX 1080TI. I had choppy playback with random dropped frames regardless of the footage. Last week I purchased a RADEON VII and put it to the test. RESULT = 0 dropped frames, much faster rendering and real time playback in Premiere. The results are much more impressive in DaVinci Resolve 15. Radeon VII is an editing powerhouse!!

@Anonymous, thanks for the script, works great!

Changing affinity while actually playing media seems to be the key.

Which suggests that this works by "tricking" Premiere into thinking it has a heavier workload than is really the case, causing it to switch to a less aggressive scheduling / threading. Why this is specific to Threadripper and newer Nvidia cards is anyone's guess...

Okay, based off the comments below and some testing, I think I have a script based workaround. It changes the affinity to 2 cores for 10 seconds and then to 24 since I have 24 threads. If you have 32 threads (1950X or the likes) replace 0xFFFFFF in the second command with 1FFFFFFFF. This is simply a HEX number so you can use the windows calculator in programmer mode to calculate the required HEX number.

1. Create a powershell script (.ps1) in notepad or Powershell ISE with this code:

$APPCCset = Get-Process -ProcessName "Adobe Premiere Pro"
foreach ($APPCC in $APPCCset) {$APPCC.ProcessorAffinity=0x3}

Start-Sleep -s 10

$APPCCset = Get-Process -ProcessName "Adobe Premiere Pro"
foreach ($APPCC in $APPCCset) {$APPCC.ProcessorAffinity=0xFFFFFF}

2. You'll need to change your powershell execution policy to RemoteSigned in Powershell:

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned

The important part, Premiere must be playing back some media. If it's paused, changing affinity doesn't affect premiere no matter what you do.

3. Run the script while playback, may take 1-2 tries. The next time playback is initiated it should work.

This is what has reliably gotten me by, hope it works for you.

I'm using an RTX 2080TI, 2990WX, Win 10. I had to go back to CC2018 for both AE and Premiere and both apps are still chugging. Timeline scrubbing is pitiful compared to my 2017 MBP. All sorts of other app lags as well. Sounds like it might be another Geforce driver issue from what I read below. But, who knows... can we get some devs on this new tech asap!?

To the comment below about using Davinci Resolve, you're right. I've even got a copy from buying a camera from BMD. Problem I have with Resolve is that it's not great as a NLE. I hate the locked down UI and there's no full screen output without an add in card. DR makes you adapt to it rather than the other way around. Otherwise I would switch to it in a heartbeat, right now I rather switch to Final Cut Pro on OSX than DR.

Ok enough is enough. This thread has been active for months and Adobe won't fix it. PLEASE ABANDON PREMIERE and switch to Resolve! DaVinci Resolve uses all of your hardware and produces content in 32 bit float color depth by default. It's at least double the speed, contains audio editing, the industry standard for colour grading and a pro VFX suite. All for $400 Canadian FOR LIFE. Please, please just take my advice. You will thank me