Problem with Frame-Rendering Times

[Jonas26731151408l]

Hey guys, as you can see in the title I have a problem with the frame-rendering time: 

When I apply a bit more complicated effects (e.g. Pixel Motion Blur) in my project, the time for the frame-rendering gets extremely high (up to 1s per frame), even when I set the workspace bar very low, like 1-2 seconds.

I already activated Mercury-GPU-Acceleration (CUDA) and Multi-Frame-Rendering, set the Disk Cache up to several hundred GBs (I know it doesn't have to be that high but just in case), of course updated my graphic drivers and gave After Effects 11 GB of my RAM.

The thing that's weird is, the Task Manager shows only a pretty low utilization when actively rendering complicated effects: around 40% CPU, 70% Memory, 30% GPU and 0% Disk.

My specs are the following:

Windows 10 Home

Nvidia Geforce RTX 2070 Super

Intel i7-8700k

16 GB RAM

200 GB SSD on which I installed After Effects 

1.8 TB SSD on which I put the Disk Cache

I hope you can help me with this problem, thanks in advance.

[Jonas26731151408l]

Thanks for the help!

[Warren Heaton]

Running After Effects on a system with a faster processor will improve render time.

[jenkmeister]

Pixel motion blur results in multiple frames having to be rendered to feed into the output of a single frame. So that's naturally going to slow down the speed that frames are rendered. 11GB of available RAM to AE will also fill up very quickly and then AE will need to spend a good amount of time writing rendered frames to disk to free up memory which will also slow down the renders.

I don't see what resolution you are working in nor the bits per channel, both of which may also be slowing down your rendering on lower levels of RAM.

[Jonas26731151408l]

Thanks for the answer. 

Motion Blur is deactivated in my project. 

I recently upgraded my RAM, it's 40gb allocated to After Effects now.

I'm working in 1080p, but halved it in the preview panel.

I have a bit depth of 8-bit per channel if that's what you meant.

[֑nubnubbud]

you won't get much better. 
https://www.pugetsystems.com/solutions/video-editing-workstations/adobe-after-effects/hardware-recom...
you can see in these validated tests, that everything from $12000 render farm stuff to $2000 midrange PC's, the render speed difference won't be night and day. I would say probably about 60% of the resources used are for backend processes that don't increase performance, but just "need to happen" for the program to do the thing at all. They even give you the benchmark so you can compare! handy!

"After Effects used to make great use of high core count systems (including dual Xeon) but starting with AE CC 2015 most tasks no longer benefit from having a high number of CPU cores. This is largely due to the fact that Adobe removed the “render multiple frames simultaneously” feature in part due to the fact that they are starting to integrate GPU acceleration. It used to be that more cores = faster... but because higher core count CPUs run at a lower speed, a CPU with around 8 cores will be faster than a higher core count CPU or even a dual CPU setup. Multi-frame rendering brought some of this back, but from our test data it doesn’t scale well enough for a dual CPU workstation to give an advantage over a single, high core count CPU." -Puget Systems

is the not-so-short and long of it.

also, more RAM won't hurt. 64GB should be goot for 1080p, but you'll want to max it out or get at least 128 for 4k... though sadly, given AE's performance, filling up that RAM for playback is gonna be a pain and take a while because apparently 9 years is not enough time to convert the most common 32 effects to GPU compute.

[Jonas26731151408l]

Thanks for replying and researching!

But as I said, I already have 40gb of RAM allocated to After Effects and as you said, a couple more resources won't make that huge difference. I mean, my rendering times are extremely long and according to my task manager, nothing is that hard bottlenecking, so I think it's a software problem of my After Effects or it's Adobe's fault, but then again, it can't be that others have perfect render times with seemingly similar settings.

Btw sorry for replying that late

[Warren Heaton]

@Jonas26731151408l 

Are you still running After Effects on an 8th generation i7 as indicated in your May 26 post?

[֑nubnubbud]

Yeah, the program was made 30 years ago. Dedicated GPU's were a twinkle in a hardware nerd's eye and multi core CPU's were a theory in testing, and RAM hadn't hit a gig.

So basically 100% of what makes up modern computers... it can't natively use effectively. They just use RAM as a place to throw everything, then process everything on the same core unless it's a render. Then they put an entire copy of the program on each. Efficient and lightweight this is not. This is like running a kitchen  but instead of 5 chefs using 2 stoves with piped gas, they're all using MRE style single use camp stoves and have to haul refills from the back room every meal and get stuck in the hallway in and out. And because it's 2024 people are expecting a 4(k) course meal, when in the 90's a nice steak and salad would constitute a fancy meal, now that's standard and the bare minimum unless it's fast food. Metaphors get out of hand so easily.

[jenkmeister]

"Then they put an entire copy of the program on each."

This may have been true 15 years ago, but the current Multi-Frame Rendering and PF_Iterate system does not work like that. AE will send individual frames for rendering to new threads, and within each frame, the rendering pipeline, effects, etc., can all spin up new threads, or use the GPU, or partition the frame into smaller chunks for rendering - whatever is the most effective in rendering that piece of content. 

Back the original forum post, using Pixel Motion Blur forces frames to be rendered multiple times to get the neccesary pixels for the motion blur. It will slow down your output because there is simply more to do.