Very slow RAM preview with good computer specs?!

Just to pitch in my 2 cents for whomever hopes this issue is somehow fixed in Feb. 2023...it is not. High end Zephyrus Duo laptop (RTX3080), working smooth in highly complex ray-traced Unreal Engine scenes, working great in complex Blender scenes and, get this, working very smoothly in Premiere Pro - same clip I can edit and preview in Premiere, somehow has absurd lags in AR, even at quarter resolution with one frame skipping - we're talking about minute long clips. Eveything is licensed, OS and CC, everything is updated.

The only real fix is if indeed your work area is very short (seconds) and change preview settings to Cache before playback. Needless to mention that this is resulting in a slow workflow, chipping away at your creativity. 
And it's been like this since I've started editing more seriously, so several years now. 

Bottom line, other apps, including Adove suite apps work great with video content. AE simply doesn't effectively utilizes all your PC machine resources. Checking your PC performances in task manages will show your SSD is not at 100%, your processor is not at 100% (not even any single core if you look at them individually), your RAM is not full and your GPU might as well be sleeping. So AE is just a product that is not optimized for modern editing, from my point of view. 

First question, are you new to After Effects? Second question, how long is your comp? AE is designed to create shots and occasionally a short sequence, it is not a video editing app. Third question, what is the comp size and frame rate? There is almost never a reason to do a project at more than 30 fps with a frame size larger than 4K because the audience that could even see the higher frame rate or use the larger frame size is incredibly small. If you stream your video on YouTube or Vimeo it will be resized and the frame rate will be adjusted to match the available bandwidth anyway.

AE artists with experience usually work this way. Step 1: Set up any motion animation that is needed in the comp then verify that the movement and timing are correct before adding any effects and motion blur is off. The preview is usually done at 1/2 resolution or less and often skipping frames is a good idea. You just want to make sure that the timing and position are OK. I call this a Pencil Test. Animators have been using pencil tests for more than 100 years. It's a good idea.

The second test is to start working with effects and color. I call this Ink and Paint. In this phase of production, you check frames at full resolution to make sure everything is the way you want it, and you occasionally preview a few frames with everything turned on. If the Pencil Test is OK there is no need to try and preview the whole shot or sequence with everything turned on. You just have to trust that the animation is working and make sure that the hero frames (critical frames) are OK but you don't have to see them move to make sure that they are OK.

I will offer you a couple more suggestions. Try and avoid the temptation to pixel peep. The only way you can really judge the final video is to look at it in the Media Player you are going to use to present the movie. You have to render to see that. The most efficient way to get a movie done is to do the compositing, effects and motion graphics that can't be done in your NLE a shot at a time, render those shots, then do the final editing in an NLE like Premiere Pro. I know that sounds like more work but it actually takes a lot less time in the long run and if you need to make changes in 20 frames then you only have to fix those 20 frames and re-render them. That can make a difference of 10 or 20 hours when making a change in a 3 or 4-minute video.

I hope this helps.

Hi,

I have the same exact issue of after effects freezing and crashing for small moments with 32gb of ram while previewing footage.

I was working 2560x1080 60fps and I have alicated 26gb of ram to ae and yes I am read and writing cache to a ssd.

The focus of AE is to playback whatever you created. This includes a simple text moving left and right up to high complex 2D/3D animation with hundreds of effect layers. AE never focused on short rendertimes and real-time playback - and actual it's kind of slow, when it comes to rendering compared with other software like Fusion or Unity.

You GPU is overkill at the moment, since AE only use it for a couple of effects and motionblur (at least!). Also, AE runs better on high-rated CPUs instead of many cores. A i7 4-core 4,5 GHz could outperform your killer-machine. RAM is quiet nice - thumbs up!

When it comes to final output renders, you can use RenderGarden to increase render speed, especial with our many cores. Concerning the preview, there is not much you can do.

I try to keep my comps small, with a few layers only, precomps when ever possible. Also I use a dedicated 250GB SSD for cache. A good practice will be to have the same quality and resolution settings both for the RAM preview rendering (Preview Panel -> set it to automatic) and the still-image preview (Compsition panel). So every time you playback and it crunches through the frames, you won't loose this data, unless you change something - meaning the next time you playback, chances are good to have a bunch of frames already rendered.

However, having a stable 7 to 9 fps for preview is actual good. Let it render, and when watch it - that's how stuff works in composition universe.

You can also render some layers as movie or image sequence, when you know you won't change it anymore (something like a animated background, which runs in a loop which heavy effects and expressions kills your preview speed, but can easily final-rendered over night, inserted as png-sequence and won't annoy you anymore).

Cheers,

Martin

i've come here to find a solution for the exact problem with 32GB RAM, I guess I will have to deal with it