How to Fix Slow Speeds on Your Extreme Portable SSD

Portable SSD Portable | Extreme | Extreme Pro SSD
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Experiencing slow speeds on your Extreme Portable SSD can be frustrating, especially when you expect fast, consistent performance. Several factors—such as outdated firmware, incorrect USB ports, or file system issues—can cause noticeable slowdowns. Start by checking your connection. Make sure the SSD is plugged into a USB 3.1 or USB-C port, as using slower ports will limit transfer rates. Also try switching cables because worn or non-certified cables often reduce performance.

Next, update your SSD’s firmware using the SanDisk SSD Dashboard, which can significantly improve speed and stability. You can download it from SanDisk’s official tools page:
https://kb.sandisk.com/app/answers/detail/a_id/15134

If your drive is nearly full, free up at least 10–15% of space to avoid performance drops. Running a disk check or optimizing the file system can also help. On Windows, use the built-in “Optimize Drives” utility; Mac users can run First Aid through Disk Utility.

Finally, make sure your system supports UASP mode, which enhances SSD performance. If issues continue, refer to SanDisk’s troubleshooting guide:

https://kb.sandisk.com/app/answers/detail/a_id/15219

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Hi @ef_ryronald

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)

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Just to add additional tips that helps improving the read and write speed for your external drives:

  • Quit some programs that are accessing the external hard drive simultaneously.
  • Remove duplicate files and large apps that you no longer need.
  • Defragment the external hard drive if the speed remains slow.
    Resource - [Fixed!]Slow External SSD and HDD on macOS Ventura