A disk drive simulated in memory. Also called a "virtual disk," "virtual hard drive" or "emulated disk" (e-disk), selected files are copied from the hard drive to the RAM disk in order to speed up processing. Before the computer is turned off, the data must be saved to the hard drive or other permanent medium. RAM disks for personal computers perform a similar function as huge in-memory databases used by enterprises for fast decision support. However, in-memory databases automatically allocate memory and must periodically write changes to permanent storage in case of hardware failure (see in-memory database
RAM disks are also used to capture data that are intentionally not saved. When the computer is turned off, the RAM disk contents are lost.
RAM Disks vs. Disk Caches
RAM disks must be installed and configured by the user, whereas disk caches are part of the operating system. Disk caches hold chunks of disk data in memory that are frequently accessed, but they do not copy an entire file into memory for processing. See cache
Dataram's RAMDisk for Windows
A very popular utility, RAMDisk can also save and reload its contents at shutdown and startup. RAMDisk formats in FAT16 and FAT32. If the user requires NTFS, the Unformatted option simulates a raw hard drive as if it were newly installed, and it must be formatted with a disk management utility. The drive list is shown before and after the RAM disk was started.