500GB Extreme Portable SSD missing 80% of its space

USB Flash Drives Extreme Drives
1

I have a 500 GB Extreme Portable SSD. It shows 465 available space on ‘Create and Format Hard Disk Partitions’. But I am only able to copy about 125 GB. What happened to the remaining 340+ GB ???

2

Hi @usha

Have you checked our knowledge base articles?
(Get Support for Your SSDs and Flash Products | Sandisk)

Have you opened a Support Case?
If not, contact SanDisk Technical Support for assistance.
(Contact Support | Sandisk)

3

It is because some space might be taken by hidden partitions or the drive could have errors or bad spots. There could also be limits from the file system or settings. To fix this, you should check the drive for errors and look at how the partitions are set up. If needed, back up your data and reformat the drive.

4

Thank you, Usha, please use Sandisk Dashboard to check disk health.

Please use Cmd > Chkdsk for deep disk health check.

You could use a defrag tool, such as Windows Cmd > defrag, or a 3rd party tool, such as Aomei Partition Assistant > defrag.

If that does not fix it. you could create a new Windows user, local / non-microsoft.