Definition: RAM disk

A storage drive simulated in memory (RAM). Also called a "virtual disk," "virtual hard drive" or "emulated disk" (e-disk), selected files are copied from storage to the RAM disk in order to speed up processing. Before the computer is turned off, all updated data in RAM are automatically saved to storage.

RAM disks for personal computers perform a similar function to in-memory databases used by large enterprises for fast decision support. However, in-memory databases automatically allocate memory and periodically write changes to storage in case of hardware failure (see in-memory database).

RAM Disks vs. Disk Caches
RAM disks, or RAM drives if SSDs, are 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 and SSD.

Dataram's RAMDisk for Windows

RAMDisk can reload and save its contents at startup and shutdown. The drive list is shown before and after the RAM disk was started.