Extreme Portable SSD 1 TB shows less free space than it should: 258 GB are missing!


I have a San Disk Extreme Portable SSD with 1 TB capacity. There is no data hidden in invisible folders. There are 540 GB of data on it.

But: The Finder and Disk Utility show that 797 GB of data are used on the SSD. Only 202 GB are shown as free capacity.

– Why is that?
– Where is the remaining space (258 GB)?

– How can I release and use the missing memory?

Please see image for details.

Thank you!

Here are two more images of Disk Utility.

Hi @mathiasP,

Have you opened a Support Case? If not opened, for more information, please contact the SD Technical Support team for best assistance and troubleshooting:

Hi! Yes, I have opened a case just now. I will report.


Hi all! I finally found a solution for this. And it was mind-bogglingly simple…

Today (after months of frustration and inactivity in that matter), I once again had my hands on this SSD drive. It still showed the wrong size of free space: 900 MB free space on a 1000 TB SSD drive with only 571 GB data on it. That makes 428 GB missing…

So, here’s what I did:
I took a folder with 3 GB files in it and tried to copy it to the SSD. Of course, that did not work as there was not enough free space on the drive available.

In a second step, I took a folder with 700 MB data in it and tried to copy it on the SSD. The copying process started and during that I noticed that the free space value was updated from 900 MB to 426 GB!

So somehow there must have been an incorrect size value stored somewhere on the SSD, which was only updated to the correct value during the copying process!

1 Like

I am having the exact same problem. And I tried your trick of copying something to the SSD, but my available storage didn’t change. I’ve got 350GB of files on the drive, but SanDisk is only showing 171GB available. This is maddening.

The discrepancy of 258GB in the available free space on your 1TB Extreme Portable SSD could be due to file system overhead, hidden system files, partitioning/formatting issues, or reserved space. Check for hidden files, verify partitioning/formatting, and consider updating firmware to resolve the issue.
EaseUS Data Recovery software with a SanDisk SSD is its ability to effectively recover lost or deleted data from the SSD, providing a reliable solution for data retrieval in case of accidental deletion, formatting, or other data loss scenarios.SanDisk Extreme SSD Failure: Tips to Prevent from Further Damage

@imran11: Thank you for your tips and effort to help. As I had already explained on Feb 10, I no longer have that problem. The capacity is back to full extend.