What is an SFCACHE File Used For?

SFCACHE Files are ReadyBoost Virtual RAM Files & Here's How They Work

Screenshot of the SFCACHE file icon used for ReadyBoost

A file with the SFCACHE file extension is a ReadyBoost Cache file that's created on a compatible USB device, like a flash drive or SD card, that Windows is using for extra memory. It's normally called ReadyBoost.sfcache.

ReadyBoost is a feature in Windows 10, Windows 8, Windows 7, and Windows Vista where the operating system improves system performance by dedicating unused hardware space as virtual RAM - the SFCACHE file holds the data stored in this virtual RAM space.

While physical RAM is the fastest way to access data, using flash memory is even faster than accessing the same data on a hard drive, which is the whole idea behind ReadyBoost.

How To Open an SFCACHE File

SFCACHE files are part of the ReadyBoost feature and should not be opened, deleted, or moved. If you'd like to remove the SFCACHE file, disable ReadyBoost on the drive.

Disabling ReadyBoost and removing the SFCACHE file is as simple as right-clicking the device and choosing Properties. In the ReadyBoost tab, just select the option called Do not use this device. If you're looking to enable ReadyBoost, you can do that too from the same place - you have the option to use the entire device for virtual RAM or just a section of it.

Tip: I'm nearly 100% sure that the only use for SFCACHE files is with ReadyBoost, meaning there's never a need to open the file. However, if your SFCACHE file doesn't seem to have anything to do with ReadyBoost, I recommend using Notepad++ to open the file as a text file.

You may find some text within the contents of the file that can help you identify what program was used to build your specific SFCACHE file.

SFCACHE vs CACHE Files

SFCACHE files are similar to CACHE files in that they're both used to store temporary data for the purpose of repeated access and improved performance.

However, CACHE files are more of a general name and file extension for temporary files used in lots of different software programs, which is why it's safe to clear them out. See How Do I Clear My Browser's Cache? for information on doing that in Firefox, Chrome, and other browsers.

SFCACHE files are reserved for a different purpose, acting more like physical RAM and used solely with the ReadyBoost feature in Windows operating systems.

How To Convert an SFCACHE File

Most files can be converted to other formats using a free file converter but that's not the case for SFCACHE files. Since SFCACHE files are just used as a repository for files, you can not convert them to any other format.

If your file has nothing at all to do with a ReadyBoost SFCACHE file, but you do know what program is used to open it, I suggest looking for an Export menu or an option under the File > Save As menu for saving the SFCACHE file to a different format.

More Help With SFCACHE Files & ReadyBoost

See Get More Help for information about contacting me on social networks or via email, posting on tech support forums, and more.

Let me know what kinds of problems you're having the SFCACHE file or ReadyBoost and I'll see what I can do to help.

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