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Memory usage and storage

Memory requirements for viewing and rendering increase with the resolution of the composition frame, the memory requirement of the most memory-intensive layer in the composition, and the size of the project file.

After Effects renders each frame of a composition one layer at a time. For this reason, the memory requirement of each individual layer is more important than the duration of the composition or the number of layers in the composition. The memory requirement for a composition is equivalent to the memory requirement for the most memory-intensive single layer in the composition. For example, it generally takes less memory to render 30 layers at NTSC resolution than 2 layers at motion-picture film resolution.

Note: If the Render Multiple Frames Simultaneously option is selected, each background copy of the After Effects application renders one frame at a time.

When a layer includes a composition as a source item, everything in that composition must be rendered before the next layer is rendered.

The memory requirements of a layer increase under the following circumstances:

Using a larger source image
Enabling color management
Adding a mask
Adding per-character 3D properties
Using certain blending modes, layer styles, or effects, especially those involving multiple layers
Applying certain output options, such as 3:2 pulldown, cropping, and stretching
Adding shadows or depth-of-field effects

If you have no problems viewing each frame of a full-resolution, best-quality preview of a composition, then you have enough memory to render the composition. Rendering a composition into a movie takes no more memory than displaying it on-screen with the same settings.

Occasionally, After Effects may display an alert message indicating that it requires more memory to display or render a composition. If you receive an out-of-memory alert, free memory or reduce the memory requirements of the most memory-intensive layers, and then try again.

Free memory immediately with one or more of the commands in the Edit > Purge menu.

After Effects requires a contiguous block of memory to store each frame; it cannot store a frame in pieces in fragmented memory.

Use the following formula to determine the number of megabytes required to store one uncompressed frame at full resolution:

(height in pixels) x (width in pixels) x (number of bits per channel) / 2,097,152

Note: The value 2,097,152 is a conversion factor that accounts for the number of bytes per megabyte (2²⁰), the number of bits per byte (8), and the number of channels per pixel (4).

For example, a DV NTSC frame in an 8-bpc project requires 1.3 megabytes, and a D1/DV PAL frame in an 8-bpc project requires 1.6 megabytes, whereas a 1080i60 DVCPRO HD frame in a 32-bpc project requires 21.1 megabytes.

The operating system imposes certain limits on the amount of memory that an application can use. After Effects on the Mac OS X operating system can use up to 3.5 GB of RAM, although only about 3GB is actually available to the foreground application, because Mac OS X uses approximately 500MB to load the user interface libraries. After Effects on 32-bit Windows operating systems can use up to 3 GB of RAM; however, to use more than 2 GB in After Effects, you must configure Windows XP or Windows Vista appropriately. (For details, see the Microsoft website or Jonas Hummelstrand’s website: www.adobe.com/go/learn_ae_jonaswindows3gb.) After Effects on 64-bit Windows operating systems can use up to 4 GB of RAM with no special configuration.

Note: These numbers are for each After Effects process. The background processes used to render multiple frames simultaneously can each use the amount of RAM mentioned above. (See Render multiple frames simultaneously.)

Because video is typically compressed during encoding when you render to final output, you can’t just multiply the amount of memory required for a single frame by the frame rate and composition duration to determine the amount of disk space needed to store your final output movie. However, such a calculation can give you a rough idea of the maximum storage space you might need. For example, one second of uncompressed standard-definition 8-bpc video requires approximately 40 megabytes (MB). A feature-length movie at that data rate would require more than 200 GB to store. Even with DV compression, which reduces file size to 3.6 MB per second of video, this translates to more than 20 GB for a typical feature-length movie. It is not unusual for a feature-film project—with its higher color bit depth and greater frame size—to require terabytes of storage for footage and rendered output movies.

Comments

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Comments

Justin.Buser said on Sep 6, 2007 at 12:46 PM :

For anyone using Vista that wants to use more than 2 gigs of ram in After Effects this is how you do it:

run a command prompt as Administrator and enter the following:
bcdedit /set IncreaseUserVa 3072

A value of 3072 will increase your programs available memory to 3 gigabytes. If you want more than that adjust accordingly by multiplying the number of gigs you want to use by 1024 (ie. 4096 for 4 gigs, etc...)

Next run msconfig either from the same command line or by typing msconfig into the run or search fields on the start menu and hitting enter.

Go into the advanced options on the boot tab. In there you will find an option for maximum memory, set this to the same value you entered at the command line. Additionally if you have a multi processor or dual/quad core machine you can increase the number of processors used on this screen.

Hit ok to close the advanced options and then check off make all boot settings permanent and hit ok again to close msconfig. You will need to restart. After this you will see an increased amount of ram available in the After Effects memory settings.

As a cautionary note, if any of these steps seem confusing or difficult for you then you probably shouldn't try this. There are reasons that these settings are protected from casual adjustment which I would suggest researching before messing around.

Todd_Kopriva said on Dec 27, 2007 at 12:20 PM :

The Render Multiple Frames Simultaneously mode works best with 2GB of RAM for each processor core. If you have 8GB of RAM and eight cores (as with a computer with four dual-core chips), you may get better results using only four of the processor cores. For instructions on how to restrict the number of cores used for multiprocessing in Render Multiple Frames Simultaneously mode, see the Technical Support Knowledgebase:
http://kb.adobe.com/selfservice/viewContent.do?externalId=kb402403

No screen name said on Jan 11, 2008 at 11:51 AM :

A couple of import things to make a note of:

1. Firstly you should back up the current settings
bcdedit /export "C:\BCDBackup"

NOTE: to restore the previous (saved) settings if there are problems

bcdedit /import "C:\BCDBackup"

2. Take a look at this webpage for a more in depth understanding of the process involved.
http://www.prophotowiki.com/w/index.php/IncreaseUserVa

Films4U said on Jun 2, 2008 at 8:38 AM :

I am using Window XP SP2. How do I increase the amount of available memory for After Effects? Bcdedit seems to be a Vista command.

Thanks

Todd_Kopriva said on Jun 2, 2008 at 8:48 AM :

For information on using the /3GB switch with Windows XP, follow the link to Jonas Hummelstrand’s website, which is given in the main body of this page: www.adobe.com/go/learn_ae_jonaswindows3gb

If this is not the information that you're looking for, or if you have other questions, please bring them to the Adobe After Effects user-to-user forum, which is generally a better place to ask questions than in LiveDocs comments: http://www.adobeforums.com/webx/.ee6b2fe/

No screen name said on Jul 6, 2008 at 6:39 PM :

If anyone does not want to upgrade ram but after effects is telling them they have run out of memory when exporting, go edit - preferences - (click on the secret menu) then press purge every 15 frames.

bryanschaeffer said on Jul 29, 2008 at 11:59 AM :

I have 8gb of Ram on my 2.66 Dual Core Mac. After Effects shows only 3gb available. Is is possible to use all 8? How is this done? Thanks.

No screen name said on Sep 3, 2008 at 10:09 AM :

I would like to know the same thing as above I have a PC with 8 GB, Vista 64, is it even possible to use 8 gb even though cs3 programs are 32 bit.
thanks.

Todd_Kopriva said on Sep 3, 2008 at 10:25 AM :

To use all 8GB (or 16GB, or 20GB...) on a multi-core computer running a 64-bit operating system (like Mac OS X), use the Render Multiple Frames Simultaneously multiprocessing feature. With this feature, each instance (process) of the 32-bit After Effects application can use the amount of RAM described above.

If you have more questions, please use the After Effects user-to-user forum, which is a much better forum for questions and answers than is a series of comments on a documentation page.

Here's a link to the After Effects user-to-user forum:

http://www.adobeforums.com/webx/.ee6b2fe/

Justin.Buser said on Oct 15, 2008 at 3:41 PM :

Another thing to note is that you cannot use OpenGL and Multiprocessor rendering at the same time, this is because OpenGL pushes rendering processes over to your video cards' GPU whereas Multiprocessor rendering uses each system processor/core individually to render frames.