computer science

List of RAM drive software

List of RAM drive software is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of RAM drive software rather than just read about it. In short: RAM drive software 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—volatility is an advantage if security requires sensitive data…

Key takeaways

List of RAM drive software belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of RAM drive software to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of RAM drive software from memory before moving on to harder problems.

Reference excerpt

RAM drive software 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—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.

Overview

Features 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. 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. 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. Software using unmanaged memory can cause stability problems. Specifically in IBMPC based 32-bit operating systems, 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

md – memory disk 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. To create and mount memory disk with mdmfs:

# mdmfs -F newimage -s 5m md0 /mnt

To create and mount memory disk with mdconfig:

# mdconfig -a -t swap -s 5m -u 0

# newfs -U md0

# mount /dev/md0 /mnt

To destroy previously created disk:

# umount /mnt

# mdconfig -d -u 0

Linux

shm Modern Linux systems come pre-installed with a user-accessible ramdisk mounted at /dev/shm.

RapidDisk 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.

tmpfs and ramfs An example of how to use tmpfs and ramfs in a Linux environment is as follows:

$ mkdir /var/ramdisk

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:

$ mount -t tmpfs none /var/ramdisk -o size=28m

Now each time /var/ramdisk is accessed all reads and writes will be coming directly from memory. There are 2 differences between tmpfs and ramfs. 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

Non-proprietary

ImDisk 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. ImDisk Toolkit is a third-party, free and open-source software that embeds the ImDisk Virtual Disk Driver and adds several features.

AIM Toolkit AIM Toolkit is a suite of tools that allows to create ramdisks and mount image files. It is based on the open source driver Arsenal Image Mounter written by Olof Lagerkvist. All virtual disks created are handled by the Disk Manager of Windows like physical hard drives. It is developed to face more and more compatibility issues of ImDisk, especially with Windows 11. Only available for Windows 7 64-bit and later.

ERAM 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

AMD Radeon RAMDisk 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.

Dataram RAMDisk 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 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.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with List of RAM drive software

Start with the simplest possible case. Write down what List of RAM drive software claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of RAM drive software before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of RAM drive software ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of RAM drive software

In research: List of RAM drive software appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of RAM drive software in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of RAM drive software is common in secondary-school and first-year university syllabi. It links to neighbouring topics Lists of software, so understanding it makes those chapters shorter.
In everyday life: Look for List of RAM drive software outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study List of RAM drive software in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of RAM drive software means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of RAM drive software out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of RAM drive software in simple terms?

Why does List of RAM drive software matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of RAM drive software?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of RAM drive software.