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!


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.

How can a folder weighting 550GB occupy 980GB?
Has any stable solution been found to this problem?
In my SanDisk Extreme SSD Portable of 1TB, almost half the terabyte is neither filled by the folder in it nor available for other files (see screenshot). As someone above described it, it feels a bit maddening not to be able to rely on your SSD. Therefore, I would highly appreciate any help or suggestion.

I’m using macOS 10.15.

Thank you ahead for your time and suggestions!

Hello Elisabet, did you try this:

Select something (a folder e.g.) what is BIGGER than what is free on your SSD. Of course, that will not work as there is not enough free space on the drive available.

In a second step, take something SMALLER which fits on your SSD’s free space and and try to copy it to the SSD.

In my case, the copying process started and during that I noticed that the free space value was updated to the correct value.

This was my solution.
Regards, mathiasP

Dear Mathias,
Thanks for your suggestion. I tried it (again), and the problem remains.
Any other idea, please?
Have a good day,

Hey there, fellow SanDisk user here! I was experiencing similar issues with my SanDisk Extreme Portable SSD, where the Finder and Disk Utility were showing more data usage than what was actually stored on the drive. After some research, I came across a helpful giveaway by EaseUS that helped me recover the missing space and optimize the performance of my SSD.

Based on my personal experience, I highly recommend others to check it out as well. It’s always frustrating when we can’t utilize the full capacity of our storage devices, and I’m glad I found a solution to fix it. Hope this helps!

I don’t like your posts. It’s the second time you’ve posted here, and in both cases you are massively advertising a professional product that is very expensive.

You add nothing of substance.

This company (“EaseUS”) claims that “In recent weeks, SanDisk’s portable solid state drives (SSDs) have been at the center of controversy, with a sudden increase in failure rates causing widespread concern among users.”.

Where is the source, the references?

Also, EaseUS say that the alleged issues only occur with 2TB and 4TB SSDs and relate to devices manufactured in 2023. You, imran11, don’t mention this, which is unfortunate to say the least. Or even deliberately concealing it?

On the other hand, that’s my personal impression. Maybe others see it differently.

I was having the same problem. I called Sandisk technical support. My empty 1 tb extreme portable ssd was showing 549 gb of used space. The support tech suggested, since it was empty, to just reformat it. Bingo! The drive now showed only 6 MB of used space.

I had already copied all my data to a new 4 TB drive, so I was able to reformat. Another option is to copy all your data to your computer’s drives, reformat the 1 tb ssd, and then copy the data back.