A RAM drive (also called a RAM disk) is a block of random-access memory (primary storage or volatile memory) that a computer's software is treating as if the memory were a disk drive (secondary storage). It is sometimes referred to as a virtual RAM drive or software RAM drive to distinguish it from a hardware RAM drive that uses separate hardware containing RAM, which is a type of battery-backed solid-state drive.
2History and operating system specifics
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Performance[edit]
The performance of a RAM drive is in general orders of magnitude faster than other forms of storage media, such as an SSD, hard drive, tape drive, or optical drive.[1] This performance gain is due to multiple factors, including access time, maximum throughput, and type of file system.
File access time is greatly reduced since a RAM drive is solid state (no mechanical parts). A physical hard drive or optical media, such as CD-ROM, DVD, and Blu-ray must move a head or optical eye into position and tape drives must wind or rewind to a particular position on the media before reading or writing can occur. RAM drives can access data with only the memory address of a given file, with no movement, alignment or positioning necessary.
Second, the maximum throughput of a RAM drive is limited by the speed of the RAM, the data bus, and the CPU of the computer. Other forms of storage media are further limited by the speed of the storage bus, such as IDE (PATA), SATA, USB or Firewire. Compounding this limitation is the speed of the actual mechanics of the drive motors, heads, or eyes.
Third, the file system in use, such as NTFS, HFS, UFS, ext2, etc., uses extra accesses, reads and writes to the drive, which although small, can add up quickly, especially in the event of many small files vs. few larger files (temporary internet folders, web caches, etc.).
Because the storage is in RAM, it is volatile memory, which means it will be lost in the event of power loss, whether intentional (computer reboot or shutdown) or accidental (power failure or system crash). This is, in general, a weakness (the data must periodically be backed up to a persistent-storage medium to avoid loss), but is sometimes desirable: for example, when working with a decrypted copy of an encrypted file.
In many cases, the data stored on the RAM drive is created from data permanently stored elsewhere, for faster access, and is re-created on the RAM drive when the system reboots.
Apart from the risk of data loss, the major limitation of RAM drives is their limited capacity, which is constrained by the amount of RAM within the machine. Multi-terabyte-capacity persistent storage has become commoditized as of 2012, whereas RAM is still measured in gigabytes.
RAM drives use the normal RAM in main memory as if it were a partition on a hard drive rather than actually accessing the data bus normally used for secondary storage. Though RAM drives can often be supported directly from the operating system via special mechanisms in the operating system kernel, it is possible to also create and manage a RAM drive by an application. Usually no battery backup is needed due to the temporary nature of the information stored in the RAM drive, but an uninterrupted power supply can keep the entire system running during a power outage, if necessary.
Some RAM drives use a compressed file system such as cramfs to allow compressed data to be accessed on the fly, without decompressing it first. This is convenient because RAM drives are often small due to the higher price per byte than conventional hard drive storage.
History and operating system specifics[edit]
The first software RAM drive for microcomputers was invented and written by Jerry Karlin in the UK in 1979/80. The software, known as the Silicon Disk System was further developed into a commercial product and marketed by JK Systems Research which became Microcosm Research Ltd when the company was joined by Peter Cheesewright of Microcosm Ltd. The idea was to enable the early microcomputers to use more RAM than the CPU could directly address. Making bank-switched RAM behave like a disk drive was much faster than the disk drives - especially in those days before hard drives were readily available on such machines.
The Silicon Disk was launched in 1980, initially for the CP/M operating system and later for MS-DOS. Due to the limitations in memory addressing on Apple II series and Commodore computers, a RAM drive was also a popular application on Commodore 64 and Commodore 128 systems with RAM Expansion Units and on Apple II series computers with more than 64kB of RAM. Apple Computer supported a software RAM drive natively in ProDOS: on systems with 128kB or more of RAM, ProDOS would automatically allocate a RAM drive named /RAM.
IBM added a RAM drive named VDISK.SYS to PC DOS (version 3.0) in August 1984, which was the first DOS component to use extended memory. 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. Microsoft included the similar program RAMDRIVE.SYS in MS-DOS 3.2 (released in 1986), which could also use expanded memory.[2] It was discontinued in Windows 7. DR-DOS and the DR family of multi-user operating systems also came with a RAM disk named VDISK.SYS. In Multiuser DOS, the RAM disk defaults to the drive letter M: (for memory drive). AmigaOS has had a built in RAM drive since the release of version 1.1 in 1985 and still has it in AmigaOS 4.1 (2010). Apple Computer added the functionality to the Apple Macintosh with System 7's Memory control panel in 1991, and kept the feature through the life of Mac OS 9. Mac OS X users can use the hdid, newfs (or newfs hfs) and mount utilities to create, format and mount a RAM drive.
A RAM drive innovation introduced in 1986 but made generally available in 1987[3][4] by Perry Kivolowitz for AmigaOS was the ability of the RAM drive to survive most crashes and reboots. Called the ASDG Recoverable Ram Disk, the device survived reboots by allocating memory dynamically in the reverse order of default memory allocation (a feature supported by the underlying OS) so as to reduce memory fragmentation. A 'super-block' was written with a unique signature which could be located in memory upon reboot. The super-block, and all other RRD disk 'blocks' maintained check sums to enable the invalidation of the disk if corruption was detected. At first, the ASDG RRD was locked to ASDG memory boards and used as a selling feature. Later, the ASDG RRD was made available as shareware carrying a suggested donation of 10 dollars. The shareware version appeared on Fred Fish Disks 58[5] and 241.[6] AmigaOS itself would gain a Recoverable Ram Disk (called 'RAD') in version 1.3.[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.
Dedicated hardware RAM drives[edit]
There have been RAM drives which use DRAM memory that is exclusively dedicated to function as an extremely low latency storage device. This memory is isolated from the processor and not directly accessible in the same manner as normal system memory.
In 2002, Cenatek produced the Rocket Drive, max 4GB, which had four DIMM slots for PC133 memory, with up to a maximum of four gigabytes of storage. At the time, common desktop computers used 64 to 128 megabytes of PC100 or PC133 memory. The one gigabyte PC133 modules (the largest available at the time) cost approximately $1,300 (equivalent to $1,848 in 2019). A fully outfitted Rocket Drive with four GB of storage would have cost $5,600 (equivalent to $7,960 in 2019).[9]
In 2005, Gigabyte Technology produced the i-RAM, max 4GB, which functioned essentially identically to the Rocket Drive, except upgraded to use the newer DDR memory technology, though also limited to a maximum of 4GB capacity.[10]
For both of these devices, the dynamic RAM requires continuous power to retain data; when power is lost, the data fades away. For the Rocket Drive, there was a connector for an external power supply separate from the computer, and the option for an external battery to retain data during a power failure. The i-RAM included a small battery directly on the expansion board, for 10-16 hours of protection.
Both devices used the SATA 1.0 interface to transfer data from the dedicated RAM drive to the system. The SATA interface was a slow bottleneck that limited the maximum performance of both RAM drives, but these drives still provided exceptionally low data access latency and high sustained transfer speeds, compared to mechanical hard drives.
In 2006, Gigabyte Technology produced the GC-RAMDISK, max 8GB, which was the second generation creation for the i-RAM. It has a maximum of 8GB capacity, twice that of the i-RAM. It used the SATA-II port, again twice that of the i-RAM. One of its best selling points is that it can be used as a boot device.[11]
In 2007, ACard Technology produced the ANS-9010 Serial ATA RAM disk, max 64GB. Quote from the tech report: The ANS-9010 'which has eight DDR2 DIMM slots and support for up to 8GB of memory per slot. The ANS-9010 also features a pair of Serial ATA ports, allowing it to function as a single drive or masquerade as a pair of drives that can easily be split into an even faster RAID 0 array.'[12]
In 2009, Acard Technology produced the ACARD ANS-9010BA 5.25 Dynamic SSD SATA-II RAM Disk, max 64GB. It uses a single SATA-II port.
Both variants are equipped with a 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. The CompactFlash card itself is not accessible to the user by normal means as the CF card is solely intended for RAM backup and restoration. Note that the CF card's capacity has to meet / exceed the RAM module's total capacity in order to effectively work as a reliable backup.
In 2009, DDRdrive, LLC produced the DDRDrive X1, which claims to be the fastest solid state drive in the world. The drive is a primary 4GB DDR dedicated RAM drive for regular use, which can back up to and recall from a 4GB SLC NAND drive. The intended market is for keeping and recording log files. If there is a power loss the data can be saved to an internal 4GB ssd in 60 seconds, via the use of a battery backup. Thereafter the data can be recovered back in to RAM once power is restored. A host power loss triggers the DDRdrive X1 to back up volatile data to on-board non-volatile storage.[13][14]
See also[edit]
Cache (computing), an area to store transient copies of data being written to, or repeatedly read from, a slower device
LOADALL, undocumented machine instructions purportedly used by Microsoft's RAMDRIVE.SYS
References[edit]
^Kind, Tobias. 'RAMDISK Benchmarks'(PDF). University of California. Retrieved 2019-03-21.
^Zbikowski, Mark; Allen, Paul; Ballmer, Steve; Borman, Reuben; Borman, Rob; Butler, John; Carroll, Chuck; Chamberlain, Mark; Chell, David; Colee, Mike; Courtney, Mike; Dryfoos, Mike; Duncan, Rachel; Eckhardt, Kurt; Evans, Eric; Farmer, Rick; Gates, Bill; Geary, Michael; Griffin, Bob; Hogarth, Doug; Johnson, James W.; Kermaani, Kaamel; King, Adrian; Koch, Reed; Landowski, James; Larson, Chris; Lennon, Thomas; Lipkie, Dan; McDonald, Marc; McKinney, Bruce; Martin, Pascal; Mathers, Estelle; Matthews, Bob; Melin, David; Mergentime, Charles; Nevin, Randy; Newell, Dan; Newell, Tani; Norris, David; O'Leary, Mike; O'Rear, Bob; Olsson, Mike; Osterman, Larry; Ostling, Ridge; Pai, Sunil; Paterson, Tim; Perez, Gary; Peters, Chris; Petzold, Charles; Pollock, John; Reynolds, Aaron; Rubin, Darryl; Ryan, Ralph; Schulmeisters, Karl; Shah, Rajen; Shaw, Barry; Short, Anthony; Slivka, Ben; Smirl, Jon; Stillmaker, Betty; Stoddard, John; Tillman, Dennis; Whitten, Greg; Yount, Natalie; Zeck, Steve (1988). 'Technical advisors'. The MS-DOS Encyclopedia: versions 1.0 through 3.2. By Duncan, Ray; Bostwick, Steve; Burgoyne, Keith; Byers, Robert A.; Hogan, Thom; Kyle, Jim; Letwin, Gordon; Petzold, Charles; Rabinowitz, Chip; Tomlin, Jim; Wilton, Richard; Wolverton, Van; Wong, William; Woodcock, JoAnne (Completely reworked ed.). Redmond, Washington, USA: Microsoft Press. pp. 907–909, 948–951. ISBN1-55615-049-0. LCCN87-21452. OCLC16581341. (xix+1570 pages; 26 cm) (NB. This edition was published in 1988 after extensive rework of the withdrawn 1986 first edition by a different team of authors. [1]Archived 2018-10-14 at the Wayback Machine)
^Perry S. Kivolowitz (January 26, 1987). 'Overhead And Implementation Notes of ASDG RRD'. Newsgroup: comp.sys.amiga. Archived from the original on December 3, 2013.
^Perry S. Kivolowitz (January 21, 1987). 'ASDG Recoverable Ram Disk News'. Newsgroup: comp.sys.amiga. Archived from the original on January 22, 2011. Retrieved September 23, 2014.
^'README for disk 58'.
^'README for disk 241'.
^'Workbench Nostalgia: The history of the AmigaOS Graphic User Interface (GUI): Release 1.3'. Archived from the original on 2014-10-24. Retrieved 2014-09-30.
^md(4) – FreeBSD Kernel Interfaces Manual
^Mike Chin (2002-11-13). 'Blast off with Cenatek's Rocket Drive'. Silent PC Review. Archived from the original on 2018-02-03. Retrieved 2018-02-03.
^Geoff Gasior (2006-01-25). 'RAM disk without the fuss'. The Tech Report. Archived from the original on 2018-10-05. Retrieved 2018-10-05.
^Geoff Gasior (2006-06-06). 'Gigabyte boosts i-RAM speed capacity'. The Tech Report. Archived from the original on 2018-10-05. Retrieved 2018-10-05.
^Geoff Gasior (2009-01-20). 'Solid-state storage from another angle'. The Tech Report. Archived from the original on 2018-10-05. Retrieved 2018-10-05.
^'DDRdrive X1: Solid-State Storage Redefined'. DDRdrive LLC. 2014. Archived from the original on 2018-08-17. Retrieved 2018-10-05.
^Geoff Gasior (2009-03-04). 'DDRdrive hits the ground running'. PC Perspective. Archived from the original on 2018-10-05. Retrieved 2018-10-05.
External links[edit]
Unix shell command line to create a RAM disk on Mac OS X
Retrieved from 'https://en.wikipedia.org/w/index.php?title=RAM_drive&oldid=928985081'
RAM drivesoftware allows part of a computer's RAM (memory) to be seen as if it were a disk drive, with volume name and, if supported by the operating system, drive letter. A RAM drive has much faster read and write access than a hard drive with rotating platters, and is volatile, being destroyed with its contents when a computer is shut down or crashes[1]—volatility is an advantage if security requires sensitive data to not be stored permanently, and to prevent accumulation of obsolete temporary data, but disadvantageous where a drive is used for faster processing of needed data. Data can be copied between conventional mass storage and a RAM drive to preserve it on power-down and load it on start-up.
1Overview
2FreeBSD
3Linux
4Microsoft Windows
4.1Non-proprietary
4.2Proprietary
4.3Microsoft source code
5Solaris
Overview[edit]
Features[edit]
Features that vary from one package to another:
Some RAM drives automatically back up contents on normal mass storage on power-down, and load them when the computer is started.[2] If this functionality is not provided, contents can always be preserved by start-up and close-down scripts, or manually if the operator remembers to do so.
Some software allows several RAM drives to be created; other programs support only one.[2]
Some RAM drives when used with 32-bit operating systems (particularly 32-bit Microsoft Windows) on computers with IBM PC architecture allow memory above the 4 GB point in the memory map, if present, to be used; this memory is unmanaged and not normally accessible.[2] Software using unmanaged memory can cause stability problems.
Some RAM drives are able to use any 'unmanaged' or 'invisible' RAM below 4 GB in the memory map (known as the 3 GB barrier) i.e. RAM in the 'PCI hole'. Note: Do not assume that RAM drives supporting 'AWE' (or Address Windowing Extensions) memory above 4 GB will also support unmanaged PAE (or Physical Address Extension) memory below 4 GB—most don't.
FreeBSD[edit]
md - memory disk[edit]
This driver provides support for four kinds of memory backed virtual disks: malloc, preload, vnode, swap. Disks may be created with the next command line tools: mdconfig and mdmfs. An example of how to use these programs follows.[3]
To create and mount memory disk with mdmfs:
To create and mount memory disk with mdconfig:
To destroy previously created disk:
Linux[edit]
shm[edit]
Modern Linux systems come pre-installed with a user-accessible ramdisk mounted at /dev/shm.
RapidDisk[edit]
RapidDisk is a free and open source project containing a Linux kernel module and administration utility that functions similar to the Ramdiskadm of the Solaris (operating system). With the rxadm utility, the user is capable of dynamically attaching, removing, and resizing RAM disk volumes and treat them like any other block device.[4]
tmpfs and ramfs[edit]
An example of how to use tmpfs and ramfs in a Linux environment is as follows:
Once the mount point is identified the mount command can be used to mount a tmpfs and ramfs file system on top of that mount point:
Now each time /var/ramdisk is accessed all reads and writes will be coming directly from memory.[5]
There are 2 differences between tmpfs and ramfs.[6] 1) the mounted space of ramfs is theorically infinite, as ramfs will grow if needed, which can easily cause system lockup or crash for using up all available memory, or start heavy swapping to free up more memory for the ramfs. For this reason limiting the size of a ramfs area can be recommendable. 2) tmpfs is backed by the computer's swap space
There are also many 'wrappers' for the RAM disks for Linux as Profile-sync-daemon (psd) and many others allowing users to utilize RAM disk for desktop application speedup moving intensive IO for caches into RAM.
Microsoft Windows[edit]
Non-proprietary[edit]
ImDisk[edit]
ImDisk Virtual Disk Driver is a disk image emulator created by Olof Lagerkvist. It is free and open-source software, and is available in 32- and 64-bit variants. It is digitally signed, which makes it compatible with 64-bit versions of Microsoft Windows without having to be run in Test mode. The 64-bit version has no practical limit to the size of RAM disk that may be created.[7]
ImDisk Toolkit is a third-party, free and open-source software that embeds the ImDisk Virtual Disk Driver and adds several features.[8]
ERAM[edit]
ERAM is an open source driver that supports making a drive that is up to 4 GB of the total amount of RAM, uses paged/non-paged memory and supports backing up the drive to an image. It works on Windows XP/NT/2000/7/10 (32 and 64-bit). Its driver and source code can be found by going to https://github.com/Zero3K/ERAM.
Proprietary[edit]
AMD Radeon RAMDisk[edit]
AMD Radeon RAMDisk is available in free versions (RAM drive up to 4 GB, or 6 GB with AMD memory), and commercial versions for drives up to 64 GB. The free version is 'advertising supported'. Creates only a single drive (does not support multiple RAM drives). Can be backed up periodically to hard drive, and automatically loaded when the computer is started. AMD Radeon RAMDisk is a rebranded version of Dataram RAMDisk.[9]
Dataram RAMDisk[edit]
Dataram's RAMDisk is freeware (up to 1 GB (reduced from 4 to 1GB - per October 2015 site visit) disk size) and was originally developed and marketed by John Lajoie[10] through his private consulting company until 2001, when he sold his rights to Cenatek, before being acquired by Dataram. RAM disks larger than 4 GB require registration and a USD $18.99 single-user license. When purchasing physical RAM from Dataram, the RAMDisk license is provided free of charge. (Per DATARAM Government Sales on 4/25/2014, this is no longer the case.) Compatible with all 32-bit and 64-bit versions of Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, Windows Server 2008, and Windows Server 2003.[11]
Dimmdrive RAMDisk[edit]
A RAMdisk built specifically for gamers which features real-time file-synchronization, Steam (software) integration, 'USB3 Turbo Mode'. The interface was designed to support both technical and non-technical game enthusiasts. Cost is $29 at Dimmdrive.com and $30 on Steam. ($14.99 on steam as of 2018) [12]
Gavotte RamDisk[edit]
Can use Physical Address Extension to create a virtual disk in memory normally inaccessible to 32-bit versions of Microsoft Windows (both memory above the 4 GB point, and memory in the PCI hole).[13] There is also an open source plugin that replaces the RAM drive on Bart's PE Builder with one based on Gavotte's rramdisk.sys.[14]
Gilisoft RAMDisk[edit]
RAMDisk software for Windows 2000/2003/XP/Vista/Windows 7 (x32 & x64)/Windows 10 with simple setup, permits mounting-and-unmounting of RAMDisk images to/from drive-image-files, and automated/convenient startup/shutdown features, $25[citation needed].
Gizmo Central[edit]
Gizmo Central is a freeware program that can create and mount virtual disk files. It also has the ability to create a RAM disk.[15]
Passmark OSFMount[edit]
Passmark's OSFMount supports the creation of RAM disks, and also allows you to mount local disk image files (bit-for-bit copies of a disk partition) in Windows with a drive letter. OSFMount is a free utility designed for use with PassMark OSForensics.[16]
Primo Ramdisk[edit]
Romex Software Providing a fancy interface which is working with all windows environments from (XP to windows 10) and all windows servers editions from (2003 to 2019 currently) supports up to 128 Disks up to 32GB for Pro Version and 1TB for Ultimate and Server editions, supports to use invisible Memory in 32bit versions of windows, with saving at shut down or hibernate, Paid and trial versions available [17]
QSOFT ( WinRamTech ) Ramdisk Enterprise[edit]
A RAM Disk compatible with all Windows Workstation and Server OS versions (32- and 64-bit) starting from Windows 2000. Prices vary from $9 to $11. The content of the RAM Disk can be made 'persisted' i.e. saved to an image file on the hard disk at regular times and/or at shutdown, and restored from the same image file at boot time. Because of the built-in disk format routines and the built-in load of the image file, this ramdisk drive is already fully accessible at the bootstage where Services and automatically started programs are launched. Certain concurrent running benchmarks of two ramdisks at the same time reveal that this ramdisk is almost the fastest version. A fresh full-featured evaluation version is provided every year around August and allows users to update their nearly expiring version. Although the development of this RAM Disk was ended on 2017 the ramdisk version 5.3.2.15 may still be purchased.[18]
SoftPerfect RAM Disk[edit]
Available for Windows XP, 2003, 2008, Vista, 7, 8 and 10. Can only access memory available to Windows (i.e. the RAM disk is limited to the same ca. 3.25 GB as the Windows 32-bit system). To use physical memory above 4 GB you must use a 64-bit system. Multiple RAM disks can be created, and these can be 'persisted' i.e. saved to, and restored from, a hard disk image. Note: Works well except for the special 'Harddisk emulation' part tends to crash or become unstable when used with the updated windows 10 anniversary edition.[19] Home use licence is $29 (Before 11/05/2016 it was free for non-commercial use. Last free version was 3.4.8[20]). A commercial use license starts at $49, and discounts are offered for quantities over 5.[21]
StarWind Software makes a freeware RAM disk software for mounting memory as actual drives within Windows. Both x86 and x64 versions exist.
Ultra RamDisk[edit]
RAMDisk software which can also mount various CD images formats, like iso, ooo, cue, ccd, nrg, mds, img.[22] The application has two versions, paid and free where the latter allows to create a single ram disk up to 2GB in size.[23]
VSuite Ramdisk[edit]
The Free Edition (limited to Windows 32-bit Win2000 / XP / 2003) is able to use 'invisible' RAM in the 3.25 to 4 GB 'gap' (if your motherboard has i946 or above chipset) & is also capable of 'saving to hard disk on power down' (so, in theory, allows you to use the RAM disk for Windows XP swap file and survive over a 'Hibernate'). Whilst the free edition allows multiple RAM disk drives to be set up, the total of all drives is limited to 4096 MB. The current version, VSuite Ramdisk II, has been rebranded as 'Primo Ramdisk', all versions of which are chargeable.[24]
Microsoft source code[edit]
Ramdisk.sys sample driver for Windows 2000[edit]
Microsoft Windows offers a 'demonstration' RAM disk for Windows 2000 as part of the Windows Driver Kit. Limited to using the same physical RAM as the operating system. It is available as free download with source code.[25]
RAMDisk sample for Windows 7/8[edit]
Microsoft provides source code for a RAM disk driver for Windows 7 and 8 [26]
Native[edit]
Windows also has a rough analog to tmpfs in the form of 'temporary files'. Files created with both FILE_ATTRIBUTE_TEMPORARY and FILE_FLAG_DELETE_ON_CLOSE are held in memory and only written to disk if the system experiences high memory pressure.[27] In this way they behave like tmpfs, except the files are written to the specified path during low memory situations, rather than to swap space. This technique is often used by servers along with TransmitFile to render content to a buffer before sending to the client.
Solaris[edit]
Ramdiskadm[edit]
Ramdiskadm is a utility found in the Solaris (operating system) to dynamically add and destroy ramdisk volumes of any user defined sizes. An example of how to use ramdiskadm to add a new RAM disk in a Solaris environment is as follows:
To destroy the RAM disk:
All created RAM disks can be accessed from the /dev/ramdisk directory path and treated like any other block device; that is, accessed like a physical block device, labeled with a file system and mounted, to even used in a ZFS pool.[28]
DOS[edit]
FreeDOS includes SRDISK
MS-DOS 3.2 includes RAMDRIVE.SYS
PC DOS 3.0 includes VDISK.SYS
DR-DOS included VDISK.SYS
Multiuser DOS included an automatic RAM disk as drive M:
References[edit]
^'AMD Radeon RAMDisk: How it works'. Radeonmemory.com. Retrieved 2013-11-17. – invalid link !
^ abc'AMD Radeon RAMDisk FAQ: 'Q: Can RAMDisk use memory not available or seen by 32-bit Windows? A: RAMDisk cannot make use of memory that is not available in 32-bit Windows systems between 3 and 4 GB. [Commercial] RAMDisk can use memory not 'seen' by 32-bit Windows ABOVE 4 GB'. Radeonmemory.com. Retrieved 2013-11-17.
^Homepage of Jens Scheffler (2012-06-30). 'How to use full 4 GB RAM in Windows 7 32 Bit (Gavotte RAMDisk in Windows 7)'. Jensscheffler.de. Retrieved 2013-11-17.
^'Sourceforge: Ramdisk plugin for Bart's PE Builder'. Rramdisk.sourceforge.net. 2008-01-04. Retrieved 2013-11-17.