Solved: After Effects Won’t RAM Preview Whole Composition

This tutorial teaches you how to fix After Effects when it won’t or will not RAM Preview or play the whole Composition.

Understanding RAM and After Effects with Playback

When you “play” your Composition in After Effects you do something called a RAM Preview. Basically when you do this, After Effects loads as much of the video as possible into your computer’s RAM so you can view a smooth playback. AE isn’t quite like Premiere or Final Cut or other traditional NLEs — there’s usually a lot going on with lights and cameras and blending modes, etc. So it doesn’t just “play” like you were hitting the spacebar in Avid Media Composer.

If you don’t have a lot of RAM either in general or available for After Effects, it won’t play the entire Composition. It will load as much of it as possible (that green bar that slowly builds once you hit RAM Preview) and then play what it can.

So, let’s discuss a few ways to improve your RAM Preview playback in After Effects for when it won’t play the whole Composition.

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How to Improve RAM Preview Playback in AE

Here are three tips to help improve RAM Preview when After Effects won’t play the whole Composition.

Drop Playback Resolution

In the Composition panel, find the Playback Resolution dropdown menu in the lower left corner. Set this to Quarter. Now After Effects will be doing a RAM Preview at one fourth the quality. Essentially you made it 4x easier for your computer to playback the Composition by doing this.

After Effects playback resolution dropdown menu with Quarter highlighted
Set the Playback Resolution to Quarter to play more of your AE Composition

Now when you drop the Playback Resolution the playback obviously won’t be crystal clear. There will be some pixelization. If you need to view the entire Composition at full resolution, you’ll have to export out a file like an H.264 .mp4 file.

Close Out of Other Programs

If you aren’t aware, having too many programs open even if you aren’t using them makes your computer slower. All the open programs or applications eat precious RAM that After Effects needs.

When After Effects won’t play the whole Composition, close out of every program that isn’t AE. Yes, that includes Chrome and Premiere. Play Spotify off of your phone. Outlook or Gmail can wait a few minutes while you sort this out.

👏 Close 👏 out 👏 of 👏 other 👏 programs 👏

Give More RAM to After Effects

You can actually give After Effects more RAM from your computer in order to play the entire Composition or just improve responsiveness. To do this go under Preferences and then Memory & Performance.

At the top of the Preferences box that pops up in the Memory & Performance tab you’ll see two lines of text — Installed RAM and RAM reserved for other applications. Installed RAM is how much RAM is on your computer. You can’t change this (well, not without actually inserting new physical RAM in it which is way way way beyond this article’s scope). For RAM reserved for other applications, lower this number as much as you are comfortable or as much AE will let you.

After Effects' Memory & Performance preferences to improve RAM playback when AE won't play entire Comp
Lower the amount of RAM reserved for other applications

For me having 64 GB of RAM on my computer, leaving 12 GB free is fair. Note that After Effects won’t allow you to go below a certain amount as your computer still needs some RAM to do other tasks.

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If you’ve read this tutorial and you still can’t figure it out, please leave a comment and I’ll do what I can to help troubleshoot it. But if you can now fix when After Effects won’t RAM preview your whole Composition, I hope you stick around and check out some of the other After Effects tutorials on my website or consider signing up to get notified about new blog posts and happenings around EVF.

– Josh

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