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Render multiple frames simultaneously

After Effects can start additional processes of the After Effects application to run in the background to assist the main application with the rendering of frames for RAM previews or final output. These background processes have the name AfterFX.exe (Windows) or aeselflink (Mac OS).

Each background process renders its own frame and runs on a separate processor core (CPU). The number of processes used to render multiple frames simultaneously is never more than the number of processors. The number of background processes that can run on your computer also depends on the total amount of system RAM and the amount of RAM that is assigned to the main application (Maximum RAM Cache Size). The amount of RAM required for each background process varies depending on your system configuration; at least 1GB per process is recommended.

Note: You can check the current value for Maximum RAM Cache Size by choosing Edit > Preferences > Memory & Cache (Windows) or After Effects > Preferences > Memory & Cache (Mac OS).

If background processes are used for rendering, then the main foreground application is not also used for rendering. This means that creating background processes only adds to the total number of processes used for rendering if there are enough resources for at least two background processes to run.

Choose Edit > Preferences > Multiprocessing (Windows) or After Effects > Preferences > Multiprocessing (Mac OS).
Select Render Multiple Frames Simultaneously.

The bottom of the Preferences dialog box shows how many additional processors (in addition to the worst-case scenario of one processor) will be used at the current settings. To increase the number of background processes that can run, decrease Maximum RAM Cache Size or install more RAM.

Selecting the Render Multiple Frames Simultaneously option does not immediately start the background processes. The background processes start when the first render operation (for a RAM preview or for final output) is initiated after the option is selected. The background processes continue running until the option is deselected.

Important: You may experience a small delay when the background processes start for the first time, when the first render operation occurs. A message in the Info panel indicates when the background processes are initializing. Deselecting Render Multiple Frame Simultaneously stops the background processes; reselecting the option causes the same delay when the next render operation begins.

Because antivirus software operates by monitoring every read and write operation, such software can decrease rendering speed, especially with the Render Multiple Frames Simultaneously preference selected.

If the rendering of a single frame requires more RAM than is available to the individual background processes, then After Effects will not render multiple frames simultaneously and will instead use only the main foreground process to render all frames for that composition. If After Effects can’t use background processes to render multiple frames simultaneously, a message appears in the Info panel.

Note: After Effects can also use multiple processes to accelerate rendering of a single frame. This form of multiprocessing can take advantage of hyper-threading. The number of CPUs that After Effects reports in the Multiprocessing Preferences dialog box for accelerating rendering within a single frame counts the virtual (logical) CPUs available due to hyper-threading.

Comments

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Comments

Todd_Kopriva said on Dec 27, 2007 at 12:19 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

lloydalvarez said on Jan 23, 2008 at 6:08 AM :

In 8.0.2 or higher:

When all 8 cores try to render a complex or memory intensive composition with Render Mutliple Frames Simultaneously, the application can become memory starved if each process has insufficient memory. To remedy this, there is a text preference to control the maximum number of cores that Render Multiple Frames Simultaneously will use. Open the text preference file and look in the ["MP"] section for: "MaxNumberOfProcesses" = "0". "0" is the default setting, which disables this preference setting. For better performance on an 8-core machine with 8GB RAM, for example, change the "0" setting to "4" and save the preference file and restart After Effects. This restricts multiprocessing with RenderMultiple Frames Simultaneously to 4 cores, each getting approximately 2GB of RAM.

No screen name said on Mar 6, 2008 at 1:04 PM :

1.Quit After Effects.
2.Open the After Effects text preferences file, Adobe After Effects 8.0 Prefs.txt, located in the following folder:
Mac OS: Users/<username>/Library/Preferences/Adobe/After Effects/8.0
Windows XP: C:\Documents and Settings\<username>\Application Data\Adobe\After Effects\8.0
Windows Vista: C:\Users\<username>\AppData\Roaming\Adobe\After Effects\8.0
3.Find the ['MP'] section.
4.Change the "MaxNumberOfProcesses" value to "6".
5.Save and close the preferences file.

Todd_Kopriva said on Jun 23, 2008 at 9:46 AM :

You cannot use the Render Multiple Frames Simultaneously multiprocessing feature while also using OpenGL to render RAM previews or render for final output. The Render Multiple Frames Simultaneously feature works by using background processes on multiple CPU processor cores to render frames. OpenGL processing uses the GPU.

lloydalvarez said on Aug 14, 2008 at 6:47 AM :

I updated my Throttle script to support changing the
MaxNumberOfProcesses preference easy within an embed-able panel. The
script also allows changing the "Allow Idle Rendering" pref which allows AE
to continue rendering the Comp frame if you switch away to another
application. You can get Throttle here:

http://aescripts.com/2008/08/13/throttle-11/