Finder says the drive is 1.8 TB used. You can only account for 600 GB of project media. Where is the missing terabyte? Almost always in five specific hiding spots that the file system is actively concealing from you.
Tracking down phantom storage is like trying to figure out where the production budget went after wrap. There is a paper trail, but it is buried under per-diem receipts, gear rental invoices, and a coffee tab nobody can explain. The money is real. The records are scattered.
Here are the five places your missing storage is almost certainly hiding.
The Five Hiding Spots
1. Adobe Premiere Media Cache
The single biggest culprit on most drives. Premiere generates a cache file (.cfa for audio, .pek for waveform peaks, .mpgindex for indexed video) for every clip you import. These files often outgrow the source media by 5x on long projects.
By default, Premiere puts the cache wherever it wants. The first place to check: ~/Documents/Adobe/Common/Media Cache Files/ and ~/Documents/Adobe/Common/Media Cache/. But if you ever changed the cache location in Preferences, it could be anywhere on your drive.
On a project drive that has been running for two years, the Media Cache folder commonly hits 200-400 GB by itself.
2. After Effects Disk Cache
After Effects keeps a separate disk cache used to speed up RAM Preview and frame regeneration. Default location: ~/Library/Caches/Adobe/After Effects [version]/Disk Cache - [machine name]/.
The cache is sized in AE's preferences (Memory & Performance), and the default is "as much as possible" up to the disk limit. On a fast machine left running for months, this can easily hit 100+ GB without you knowing it exists.
3. Final Cut Pro Optimized and Proxy Media
FCP X bundles project media inside a .fcpbundle package, but inside that package are folders called Render Files, Transcoded Media, and Original Media. The Transcoded Media folder holds optimized media (ProRes versions of camera-original H.265, for example) and proxies. These can double or triple the size of the underlying camera originals.
Right-click the .fcpbundle and "Show Package Contents" to see what is in there. It is rarely small.
4. Time Machine Local Snapshots
This is the sneaky one. macOS keeps Time Machine snapshots locally on internal and external drives, even when you are not actively backing up. They appear as "System Data" or sometimes nothing at all in Finder, but they can occupy hundreds of gigabytes invisibly.
Run tmutil listlocalsnapshots /Volumes/[YourDrive] in Terminal to see them. To remove: tmutil deletelocalsnapshots [snapshot-name]. This is non-destructive (your real Time Machine backup on the network drive is unaffected) but it instantly reclaims hidden space on the local drive.
5. .Trashes and .Spotlight-V100
When you "delete" a file from an external drive on a Mac, it goes to a hidden .Trashes folder on that drive, not to your main system trash. If you disconnect the drive without emptying the trash, those files sit there indefinitely.
Reconnect the drive, open the trash, and empty it. On long-disconnected externals, the .Trashes folder can hold years of "deleted" files that were never actually freed.
.Spotlight-V100 (the Spotlight search index) is usually small but can grow surprisingly large on drives with millions of small files. Less common as a major culprit, but worth knowing about.
How to Actually See What Is There
The Finder is bad at showing you size by folder. You need a real disk visualization tool.
OmniDiskSweeper is free and old-school. Lists folders by size in a column view. Excellent for nuking specific folders quickly. Best when you know roughly where to look (cache directories, specific project trees).
GrandPerspective is also free and gives you a visual treemap of the entire drive. Big rectangles equal big folders. You can spot a 200 GB Media Cache folder in about three seconds. Best for "I have no idea what is taking up space" situations.
DaisyDisk is paid (around $10) and prettier than either. Sunburst visualization, very fast scan. Worth the money if you do this regularly.
**du -sh */** in Terminal is the fastest way if you are comfortable with the command line. Run it from any directory and you get a sorted list of subdirectory sizes. Pair with sort -h for human-readable sorted output.
For drives over a few TB, the GUI tools take a few minutes to scan. Let them finish before you start deleting things.
Why These Caches Grow Without Limit
Adobe and Apple set the defaults badly on purpose. The reasoning: cache speeds up the user experience, so make it as big as possible. The downside is your problem, not theirs.
Adobe defaults to no automatic cleanup. Premiere's cache settings include a "delete cache files older than X days" option, but it is set to disabled by default. Until you turn it on, the cache grows forever.
Adobe writes to wherever it wants. Even if you set the cache location to an external drive, Premiere sometimes writes to the system drive too. Double-check both locations.
FCP X transcodes are opaque. When you import in FCP and choose "create optimized media" or "create proxy media," those files go inside the bundle and FCP does not surface their size separately. You discover them when the drive is full.
Time Machine snapshots are designed to be invisible. They are intended to provide rollback without you having to think about them. The downside is exactly that you do not know they are there until you check.
The Cleanup Map
Here is the order to attack the five hiding spots. Always work top to bottom.
| Hiding spot | Risk | Likely savings |
|---|---|---|
| Premiere Media Cache | Zero (regenerates) | 50-400 GB |
| After Effects Disk Cache | Zero (regenerates) | 20-150 GB |
| Time Machine local snapshots | Zero (online backup unaffected) | 50-300 GB |
| .Trashes (external drives) | Zero (already deleted) | Variable |
| FCP optimized media | Low (regenerates from camera originals) | 100-500 GB per project |
After clearing these, run the disk visualizer again. You will usually find that the gap between what Finder shows and what you can account for has closed dramatically.
If it has not, the next likely culprit is unused project media: footage you imported, considered, and never placed on a timeline. The storage calculator can help you estimate how much of your real working set should be active media versus overhead, which gives you a baseline to compare against.
Set Reasonable Cache Limits Going Forward
Once you have cleaned up, set the caches so this does not happen again.
In Premiere: Preferences > Media Cache. Enable "Automatically delete cache files older than 90 days." Set "Maximum cache size" to something reasonable like 100 GB. Both settings are off by default. Turn them on.
In After Effects: Preferences > Memory & Performance. Set the Maximum Disk Cache Size to a sane number, often 50-100 GB depending on your drive size.
In FCP X: when importing, leave "create optimized media" off unless you actually need it for performance. Most modern Macs play H.265 fine without transcoding.
For Time Machine snapshots: nothing to configure. macOS rotates them automatically when the disk gets near full, but if you want to delete them sooner, the tmutil command works.
Before You Buy a Bigger Drive
Half the time, "my drive is full" is a cache problem. The other half, it is unused project footage. Clip Sweeper scans your Premiere projects and tells you exactly which media files are referenced on a timeline and which are sitting in bins doing nothing. Combined with a cache cleanup, it usually buys back enough space that you forget why you were thinking about buying a bigger drive in the first place.