Adobe 65008009 - After Effects CS4 Using Manual page 640

Last updated 12/21/2009
If disk caching is enabled, After Effects can store rendered items to your hard disk when the RAM cache is full during
standard previews. The disk cache is not used for RAM previews. As with the RAM cache, After Effects only uses the
disk cache to store a frame if it's faster to retrieve a frame from the cache than to rerender the frame.
• To use the disk cache, choose Edit > Preferences > Media & Disk Cache (Windows) or After Effects > Preferences
> Media & Disk Cache (Mac OS), and select Enable Disk Cache. Select a folder to contain your cache, and click OK
(Windows) or Choose (Mac OS).
For the best performance, select a folder that's on a different physical hard disk than your source footage. If possible,
the folder should be on a hard disk that uses a different drive controller than the disk that contains your source footage.
The disk cache folder can't be the root folder of the hard disk.
The Maximum Disk Cache Size setting specifies the number of megabytes of hard disk space to use. This setting should
be at least 2 gigabytes (GB).
The RAM cache and disk cache are automatically purged when you quit After Effects.
To purge the RAM cache and disk cache, choose Edit > Purge > Image Caches.
Note: Even when disk caching is enabled, each frame must be able to fit into a contiguous block of RAM. Enabling the
disk cache doesn't help with limitations regarding inadequate RAM to hold or render a single frame of your composition.
The media cache
When After Effects imports video and audio in some formats, it processes and caches versions of these items that it
can readily access when generating previews. Imported audio files are each conformed to a new .cfa file, and MPEG
files are indexed to a new .mpgindex file. The media cache greatly improves performance for previews, because the
video and audio items do not need to be reprocessed for each preview.
Note: When you first import a file, you may experience a delay while the media is being processed and cached.
A database retains links to each of the cached media files. This media cache database is shared with Adobe Premiere
Pro, Adobe Encore, and Adobe Soundbooth, so each of these applications can each read from and write to the same
set of cached media files. If you change the location of the database from within any of these applications, the location
is updated for the other applications, too. Each application can use its own cache folder, but the same database keeps
track of them all.
❖
Choose Edit > Preferences > Media & Disk Cache (Windows) or After Effects > Preferences > Media & Disk Cache
(Mac OS), and do one of the following:
• Click one of the Choose Folder buttons to change the location of the media cache database or the media cache itself.
• Click Clean Database & Cache to remove conformed and indexed files from the cache and to remove their entries
from the database. This command only removes files associated with footage items for which the source file is no
longer available.
Important: Before clicking the Clean Database & Cache button, make sure that any storage devices that contain your
currently used source media are connected to your computer. If footage is determined to be missing because the storage
device on which it is located is not connected, the associated files in the media cache will be removed. This removal results
in the need to reconform or re-index the footage when you attempt to use the footage later.
Cleaning the database and cache with the Clean Database & Cache button does not remove files that are associated
with footage items for which the source files are still available. To manually remove conformed files and index files,
navigate to the media cache folder and delete the files. The location of the media cache folder is shown in the Conformed
Media Cache preferences. If the path is truncated, click the Choose Folder button to show the path.
USING AFTER EFFECTS CS4
Memory, storage, and performance
634