Massive lag on playback and edit but only on one Project

[Strongbow]

AMD Ryzen 9 3900X 12-Core Processor 3.80 GHz

64.0 GB DDR4 RAM

NVIDIA G-Force GTX 970 graphics

Windows 10

Premiere Pro CC v15.2.0

 I'm working on a few projects (all with multicam sequences - 5 camera at 1080p). However, one project has started to lag like I'm running it on an Atari 2000 when working in the timeline

Have tried: 

- disabling all effects

- turning on CUDA

- turning playback res to 1/4

- purging media cache files

- optimised rendering

- disable transit

- disable refresh growing files

- scouring the internet for more insights

Weirdly, other projects which are basically identical do not have this problem

Any ideas?

[R Neil Haugen]

Have you tried creating a new project file, then from Media Browser, navigating to and importing the sequences of that project? This sometimes gets around a project with a glitch in it.

Neil

[Strongbow]

Thanks, tried but no success!

[Kevin-Monahan]

Hi S,

5 streams of Long-GOP media sounds like a challenge. Give us specs on your media. Is the media on a separate high speed drive? Let us know.

Thanks,
Kevin

[Strongbow]

Like I say, I've got other projects on the same drive which also have 5 streams of GOP without a problem

Software on 1TB BarraCuda 510 M.2 NVMe SSD

Media on 3.5" SATA III 6GB 5400RPM 256MB Cache

SB

[Andy 1968]

Not sure what the probelm is with this one project but I can say the GTX 970 is the weakest link in your system. You should have an RTX 2080 Ti to match your 12 core CPU. 

[Strongbow]

Indeed - waiting for the prices to drop before getting RTX 3070

Thanks to bicoin mining and suez prices are ridiculous.

However, the gtx 970 has worked fine on the same kind of projects as same res with same multicam, so although I agree, the GPU is not the problem here!

[Andy 1968]

I stated I don't think the GPU is the issue with this project. I am saying if you did track mattes or multiple layers with multiple luts the GPU will propably hit a bottle neck before the CPU. I agree now is not a good time to buy a GPU. 

[Strongbow]

any more ideas everyone?

Pulling my hair out on this one!!