Adobe After Effects - Manual (Page 659)

Note:
Note:
multiprocessing, even when you have enough RAM for all of the processors. After Effects is a multi-threaded application that can also use
other forms of multiprocessing beyond just Render Multiple Frames Simultaneously multiprocessing, and it is possible for the processors to
become “overscheduled” if these threads are competing for the same resources as the background processes used for rendering with Render
Multiple Frames Simultaneously multiprocessing. Therefore, the best approach is to begin by using a small number of processors for Render
Multiple Frames Simultaneously multiprocessing; and then increase the number of processors used until you find the optimum number for your
computer system and compositions.
If Render Multiple Frames Simultaneously is off, the RAM allocation is is still availlable for the Cache Work Area in Background feature.
When After Effects temporarily disables multiprocessing with Render Multiple Frames Simultaneously
If After Effects can’t use background processes to render multiple frames simultaneously, a message appears in the Info panel, and After Effects
uses only the main foreground process to render all frames. These messages include the following:
“Insufficient RAM. Multiprocessing is off.”
“Incompatible effect or expression. Multiprocessing is off.”
“Incompatible preview mode. Multiprocessing is off.”
“Incompatible composition. Multiprocessing is off.”
In general, the reasons for After Effects temporarily disabling Render Multiple Frames Simultaneously multiprocessing fall into these categories:
The rendering of a single frame requires more RAM than is available to the individual background processes.
The project uses OpenGL for rendering of previews or final output. The Render Multiple Frames Simultaneously multiprocessing feature
works by using background processes on multiple CPU processor cores to render frames, whereas rendering with OpenGL works by moving
processing to the GPU. (See GPU features in After Effects.)
The composition uses an effect that relies on GPU processing. These effects are generally effects implemented with Pixel Bender.
The composition contains a live Photoshop 3D layer. (See Using 3D object layers from Photoshop.). Note that live Photoshop 3D layers are
not supported.
The composition uses an effect with a temporal component that renders much more quickly when the rendering process has access to a
cache of previous frames. These effects include some effects with a Temporal Smoothing option.
The composition uses an effect with a temporal component that requires frames to be rendered in strictly sequential order.
If a composition uses any of the following effects, the composition will not be rendered with the Render Multiple Frames Simultaneously
multiprocessing feature:
Auto Color
Auto Contrast
Auto Levels
Particle Playground
Shadow/Highlight
Some third-party effects—such as CC Time Blend and RE:Vision Effects Video Gogh—are also incompatible with the Render Multiple
Frames Simultaneously multiprocessing feature.
If you are working in a ray-traced 3D composition, the composition will not be rendered with the Render Multiple Frames Simultaneously
multiprocessing feature.
Memory pool shared between After Effects, Premiere Pro, Encore, and Adobe Media Encoder
After Effects shares a memory pool with Adobe Media Encoder, Premiere Pro, and Encore. This is indicated in the Memory & Multiprocessing
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