inefficient rendering

[Joergen Geerds]

Inefficient rendering:

Dear Adobe team, I have a super simple task in premiere, Aftereffects and Media Encoder 2025: take a 16384x8192 24fps prores lt (preview at this point, later to be replaced by a prores4444), put it in a 8192x5160 timeline, add a tiny text in the lower left and hit render to prores lt again. no transcoding, no image transformation, just a simple crop. this task takes about 60 minutes to render (for 90sec source), in all 3 applications, with multiframe rendering in AE being slower than single frame rendering, and non-gpu rendering in media encoder being faster than gpu rendering.

in comparison, the same task in davinci resolve takes less than 300 seconds (rendering to dnxhr10), about 15x faster than adobe.

my PC has zero bottlenecks for this task, threadripper, 128GB RAM, m.2 boot, project & files live on a 1000MB/sec NAS.

the reason I am asking is because i need to do this task with prores4444 as input, and notchLC as output, and I am forced to use adobe for this, because the NotchLC plugin exists only for adobe. and i need to do many of those.

I thought the NotchLC plugin was the culprit for the slow rendering, but it looks like adobe is actrually the bottle neck. this has been the case ever since i started working on this project, so 2024 and 2025 adobe releases, all behaving the same.

what can be done to get adobe to render more efficient?

just for comparison: the files come from MistikaVR, which needs less than 15min to render a 90sec 16k prores file, doing heavy processing along the way (and I consider this slow already). the crop job in adobe takes 4x longer, with practically zero computational hurdles.

[jamieclarke]

Hi @Joergen Geerds - Thank you for writing this detailed post, I have seen your post on the Premiere User group.  Can we gather some additional details from you?
I'm curious what is your use case for using the Notchlc Codec?
Can you provide the gpu that you are using as well as the driver version?
I want to confirm that you are using version 25.0.0 for your work?
Are you using any effects on your media?

You mentioned rendering to DNxHR in Resolve but not in Premiere. Could you let us know if rendering to DNxHR in Premiere produces the same result? Also, if you render to ProRes in Resolve, do you notice any differences?

[Joergen Geerds]

NotchLC is the preferred codec for virtual production, LED walls/stages. It is not my choice, but rather dictated by them.
LED stages want now massive files. 16k seems the seet spot right now, but I would not be surprised to see it jump to 24k next year.

DR (on PC) can't render prores, hence the alternative rendering to DNX... it really doesn't matter what flavor of DNX, since it is a mezzanine codec like prores. my guess would be that if DR (PC) could render prores, it would be the same (fast) speed and DNX.

I have not tested rendering to DNX from adobe. the target is NotchLC

all my comments apply to the 24 and 25 versions of ME, AE and PR

GPU and driver version also doesn't affect the render speed inside the adobe apps. the main PC has a 3090 and always had the current studio driver. the slow rendering in adobe has been the case for pretty much all of 2024 when i started working on this project. as mentioned on facebook, the adobe rendering speed is only a tad slower on al 8-year old i9 with a 1080 (also current driver, not sure if game or studio version).

as mentioned, disabling GPU rendering and multi-frame does seem to speed up the rendering speed.
i.e. just transcoding (no crop, no effects, no alpha) from prores (or DNX) to notchLC is about 2x faster in media encoder when GPU rendering is disabled (this applies to 8k and 16k clips). if there is any alpha in the project (i.e. text overlays or masking), non-gpu rendering will fail/crash media encoder, only the (slower) GPU rendering will actually render the job.

My gut feeling what could be a potential thing to look into is paging and memory fragmentation (inside adobe, not system), as it looks like rendering to 6k isn't really that bad, but once the output is 8k or larger, I see massive slowdowns. but I am not a software engineer, I leave that to your capable hands.

[Joergen Geerds]

I did some more testing, just to see how bad the effect is.

i took a prores 4444 (16b) and transcoded it to prores lt (16b), a task that should have zero computational challenge, and my PC can even play back the file via space bar (stuttery, but it plays)

ME25 transcoded the file with 0.9 fps, on the threadripper without GPU. turning on GPU rendering doubled the render time in ME...

double checked the task on my older i9 with 1080, same results, just a tad slower, but the same 2x slowdown for GPU rendering

side note: the prores4444 has no alpha channel

[jamieclarke]

Hi @Joergen Geerds - I'm asking about your GPU because rendering to NotchLC requires your gpu to have DirectX11 Support, so this could potentially be the issue on your 3090.

"Encoding and decoding is GPU accelerated as long as a DirectX11 compatible GPU is available on PC"

Can you post screenshots of your export settings.  Confirming that you are using the same settings expoting from Premiere and Media Encoder?

For future reference it would be great if you could post the exact versions that you are using.  Thank you for the information. 

[Joergen Geerds]

Just to reiterate, rendering to prores (any flavor) is slow, rendering to NotchLC is just a tad slower than prores.