RAM drives provide high-performance temporary storage for demanding tasks and protect non-volatile storage devices from wearing down, since RAM is not prone to wear from writing, unlike non-volatile flash memory.
So RAM devices do offer an advantage to store frequently changing data, like temporary or cached information.
[1] This performance gain is due to multiple factors, including access time, maximum throughput, and file system characteristics.
File access time is greatly reduced since a RAM drive is solid state (no moving parts).
Compounding this limitation is the speed of the actual mechanics of the drive motors, heads, or eyes.
The first software RAM drive for microcomputers was invented and written by Jerry Karlin in the UK in 1979/80.
The 128kB Atari 130XE (with DOS 2.5) and Commodore 128 natively support RAM drives, as does ProDOS for the Apple II.
VDISK.SYS was not available in Microsoft's MS-DOS as it, unlike most components of early versions of PC DOS, was written by IBM.
[7] Many Unix and Unix-like systems provide some form of RAM drive functionality, such as /dev/ram on Linux, or md(4)[8] on FreeBSD.
RAM drives are particularly useful in high-performance, low-resource applications for which Unix-like operating systems are sometimes configured.
There are also a few specialized "ultra-lightweight" Linux distributions which are designed to boot from removable media and stored in a ramdisk for the entire session.
There have been RAM drives which use DRAM memory that is exclusively dedicated to function as an extremely low latency storage device.
With the RAM capacity expandable in 1MB increments, its internal battery was said to be effective for between 6 and 8 hours, and, unusual for the time, it was connected via the Macintosh floppy disk port.
[11][12] In 2002, Cenatek produced the Rocket Drive, max 4 GB, which had four DIMM slots for PC133 memory, with up to a maximum of four gigabytes of storage.
Both devices used the SATA 1.0 interface to transfer data from the dedicated RAM drive to the system.
Both variants are equipped with one or more CompactFlash card interface located in the front panel, allowing non-volatile data being stored on the RAM drive to be copied on the CompactFlash card in case of power failure and low backup battery.
Two pushbuttons located on the front panel allows the user to manually backup / restore data on the RAM drive.
A host power loss triggers the DDRdrive X1 to back up volatile data to on-board non-volatile storage.