RAM Disk: tips

Ways to get more out of RAM Disk on Windows. For every setting, see the RAM Disk manual.

Ready-made folders, files and permissions

Some programs expect certain folders to exist on the RAM disk when they start. To have folders created every time the disk is mounted, list them, one per line, under Create Folders in the disk’s properties. This is available for disks without an image file.

For files as well as folders, or for custom access permissions, use an image file that the disk starts from:

1. Create an image of the size you need with Image – Create Image...
2. Mount it with Image – Mount Image..., copy your files and folders to it and set their permissions.
3. Unmount it: open Image – Mounted Images, select the image and click Unmount.
4. Add a RAM disk with Disk – Add..., choose the image in Image File Name (optional) and leave Save to File on Shutdown unticked.

The disk then starts with your files, folders and permissions every time, and any changes made to it are discarded when it is unmounted or the computer restarts.

A RAM disk that keeps its contents

A RAM disk is empty after every restart, but it can keep its contents in an image file on your hard disk:

1. Create an image of the size you need with Image – Create Image...
2. Add a RAM disk with Disk – Add... and choose the image in Image File Name (optional).
3. Tick Save to File on Shutdown and click OK.

The disk starts with the contents of the image, and its changes are written back to the image when the computer shuts down or restarts. To save more often, click Advanced in the disk’s properties and set Save contents every (minutes), or tick Save contents before system sleep.

Back up the image file now and then: if the computer fails while the image is being written, its contents could be lost.

Which file system to choose

On Windows, RAM Disk can format a disk as FAT, FAT32, NTFS or exFAT.

• FAT and FAT32 are old and limit the size of disks and files. Use them only if something specifically needs them.
• NTFS is the most capable: it supports compression, symbolic links, quotas and permissions, and it is the only file system whose RAM disks can be resized or compressed.
• exFAT is lighter and handles disks and files of any size, but has none of NTFS’s extras.

Choose NTFS if a program needs it, or if you want to resize the disk or use compression or links. Otherwise exFAT is a good choice.

On Linux, RAM Disk offers FAT32, exFAT, ext2, ext4, XFS and Btrfs, and on macOS FAT32, exFAT, HFS+ and APFS.

Moving application data to a RAM disk

The browser cache and Windows’ temporary files can be moved to a RAM disk as described in How to improve your computer performance with a RAM disk; for the TEMP folder, RAM Disk does it for you with Tools – Set Windows TEMP folder...

Some programs insist on keeping their temporary files or logs in a fixed folder. You can still move that folder to the RAM disk and leave a symbolic link, a kind of system shortcut, in its place. For example, to move C:\SomeApp to R:\SomeApp, move the folder to drive R:, then open a command prompt as administrator and type:

mklink /D C:\SomeApp R:\SomeApp

Put paths with spaces in quotation marks:

mklink /D "C:\Some App" "R:\Some App"

Some programs do not work correctly when their data is moved, so test the new arrangement before relying on it.

Changing a RAM disk’s size

To make a disk larger, right-click it in the main window, choose Resize... and enter the new size. For a disk with an image file, the image grows with it. A disk can only be made larger, and on Windows only an NTFS disk can be resized. An image that is mounted on its own can be resized with the Resize button in Image – Mounted Images.

To make a disk with an image file smaller, move its contents to a new, smaller image:

1. Create an image of the new size with Image – Create Image...
2. Mount it with Image – Mount Image... and copy the contents of your RAM disk to it.
3. Unmount it in Image – Mounted Images.
4. Open the RAM disk’s Properties and choose the new image in Image File Name (optional).
5. Restart your computer, or, if nothing is using the disk, just unmount and mount it again.

The disk now has the new size and your data, and the old image file can be deleted.