Change the disk-cache folder in After Effects’ Disk settings, then verify that a new preview writes to the external SSD. Older versions call this panel Media & Disk Cache. Moving your project file or export destination does not, by itself, move the preview cache. If your startup disk keeps filling during editing, check this separate setting first.
This guide is for an external drive you already own. The useful test is whether it stays connected and handles your working preview load reliably. A large drive that disconnects through an unreliable hub is a poor working-cache location.
Separate the three locations before you change anything
- Source footage: the original clips and images your composition references. Keep these.
- Project: the saved composition and edit instructions. Back this up.
- Disk cache: reusable rendered frames. Its location can differ from both the project and footage.
Write down the current cache folder and maximum size, and save your project. This gives you a clear rollback point if previews become less reliable after the move.
Choose the new cache folder
- Connect the SSD and confirm you can create a small test file on it in Finder.
- Open After Effects’ Settings or Preferences and find Disk or Media & Disk Cache. Menu wording varies by release.
- Use the disk-cache folder chooser to select a dedicated folder on the SSD, such as
AE Disk Cache. - Set a maximum cache size that leaves room for the other work stored on that drive. Confirm the change and restart After Effects if prompted.
Adobe describes the cache controls and recommends a fast storage device in its memory and storage guide. A cache limit is a budget for this feature; it does not reserve space for exports, source media, or another Adobe application.
Test with a real composition
Preview a short section of a project you know. Check the chosen folder in Finder afterward. Compare its size before and after, and make sure the drive remains connected during playback. If the folder stays empty, recheck the selected location before removing the old cache.
For example, on a drive with 200 GB available, assigning all 200 GB to cache leaves no working margin for a new export. Choose a smaller cap based on what you actually need to store alongside it. This is an illustrative budget, not a recommended universal cache size.
Clean up the previous location carefully
Changing the setting should not be treated as proof that the previous folder has been cleared. Inspect the exact old location you recorded. Use After Effects’ cache-clearing controls where applicable; our After Effects cache cleanup guide covers that task. Do not delete a whole Adobe folder because it is large.
If the new setup is slower, restore the recorded setting and test again with the same composition. Keep source footage and cache on separate drives when practical, but measure your own workflow before rearranging an entire project archive.
If the startup disk still fills
Watch which folder grows during a short preview, then during an export. Those are different operations and may point to different causes. A disk-space scan can help identify the growing folder; it cannot determine whether an unfamiliar project file is expendable. Stop once the cache is writing to the intended drive and there is enough working space for the job.