Veeeeery slow rendering with Sequencer

Hi, I’m rendering many sequences (some of theme repeatedly) and the rendering times are absolutely terrible - I’m rendering 1min clip about 10 minutes. GPU is not used at all, my Ryzen 3500X 12-core is used on 10% (2 cores in 70%, 2 cores around 30%). My computer is perfectly capable to run the game in 4K with maxed out settings and record it in 4K while playing.

Is there any trick how to force UE to use more CPU cores and GPU for sequnce rendering? Thank you :slight_smile:

Btw. when I render to BMP, the export is quick (almost real-time), when I export to JPG or AVI, the export is cca 4-times slower. BUT at the begiining of the render first cca 10 frames are rendered at the same speed as BMP, then the speed drops dramatically.

This could be an issue of compression and/or hard drive speed. If your hard drive cant write fast enough its going to hang on each frame until its done saving the frame. Likewise if your processor doesn’t keep up with whatever the compression algorithm is (which may not be multi threaded).

For example saving compressed .exr’s was a lot slower for me than the uncompressed ones. Though in 4.24 that issue was a lot better than in 4.23 which was very slow for me. This also got exponentially better for me when writing to an extremly quick NVME SSD which keeps up with things much better than a regular HDD.

if your playback is fine
you might have a setting on that holds the frames for a period of time for each frame

@Bmiletta . I’m using M2 SSD with write speed 3Gbps, so drive speed is not an issue. The CPU is used by 10%, only 4 cores out of 24 and only 2 of them are over 50% (AMD Ryzen3900X). My colleague with i7 has all 8 cores on 20%

@YuuJin - which setting do you have in mind?

render preview problem in 4.24 any idea we check 4.24 and 4.25 but both same problem movie render preview not show video but output video is fine any idea preview window size change???

It seems like the issue, looking back again on the thread, is definitely related to JPEG or AVI compression/wrapper. Have you tried PNG or EXR ? Curious about the performance for you on those.

I’ve only had things render slow if
in render movie settings> animation>delay every frame is on

when ray tracing is on sometimes my scenes take a while to start it’s render, but the renders are quick.
non ray tracing (dx11) the renders are almost instantaneous

or maybe you have something in your level blueprint slowing things down without knowing

@YuuJin I have Delay every frame = 0sec, **Warm Up Frames = 5 **and Delay before warm-up = 1s, because otherwise I have fade in at the beginning and I don’t want that (why is it even there, it makes absolutely no sense). If I modify Warm upr frames for Delay before warm-up it has no effect on render speed.

The weird thing is that the 1st 1 second is realtime and then the speed drops significantly.
We are not using any ray-tracing and my computer is perfectly capable of running the game in 4k 60fps with all LODs and mipmaps turned off.

@anonymous_user_449ecf01 - I’m not 100% sure (because I tried it a few months back) but I think PNG and EXR exports are the same. The only fast option is BMP. But due to our production pipeline I cannot use image export, it would complicate our work too much.

@samrat333 - I have the problem with cropped preview too since 4.24

have you tried the new movie render queue in 4.25? maybe that’ll change things
I can’t seem to get any issues, and I’m on a ryzen with gtx2080ti with raytrace,
my stuff renders out fine

@YuuJin unfortunetaly we cannot update UE because our game is finishing phase and we are not using public version of UE

I have the same problem in 4.25 using a Ryzen 3900x.
Disk, CPU & GPU hardly utilized while encoding avi and very slow…
Did you guys ever figure this out?

Same issue! my config is Ryzen 5600x and graphic card is 3060ti. Using movie render queue sooooooo slow !!! what happened!!?

Hi did you ever find a fix for this?

@Pavel_Klein I have same your issue?

Do you think this this problem on Mac version?

I render 4k in over 4 mins per frame.