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What is Non-Volatile Memory (NVM)?
Non-volatile memory (NVM) is a type of computer storage that sustains itself even after the machine has been powered down. A type of non-volatile storage, NVM is typically used to store a computer’s boot code, the built-in instructions that tell it how to switch on and which programs to execute first.
One of its earliest forms was read-only memory (ROM), where data was written directly onto a circuit during the production process or programmed into it using specialized devices. Today, NVM frequently takes the form of flash memory, which can be written onto the computer’s storage disc during ordinary operations.
Key Takeaways
- Non-volatile memory (NVM) allows data to be held on a computer even after the machine has been switched off.
- It’s a vital part of modern computing, enabling data to be retained safely without having to power computer devices constantly.
- It’s typically used to store information that the computer and end users will access repeatedly: boot instructions, operating systems, applications, and user files.
- There are two main types of NVM: electrically addressed systems and mechanically addressed systems.
- NVM is slower than volatile memory like RAM, but innovations like non-volatile memory express (NVMe) aim to address that limitation.
How Non-Volatile Memory Works
Non-volatile memory uses technologies that allow it to retain data without a constant power supply. In computing lexicon, NVM is a byte-addressable, meaning it can provide data access at the individual byte level. By preserving data even during system crashes and power outages, NVM ensures that vital files and information are held intact, reducing the risk of corruption or loss.
NVM works in tandem with a computer’s volatile memory, such as random-access memory (RAM), which provides fast temporary storage for data that needs to be accessed quickly. Non-volatile memory is normally used to store applications, files, and documents.
Types of Non-Volatile Memory
There are a variety of non-volatile memory technologies and devices. They differ in the way they transfer and retrieve data and the speed at which data transfer occurs between an application, microprocessor, or device. NVMs also differ in cost, storage capacity, write-able lifespan, and latency.
There are two main types of NVM:
Non-Volatile Memory vs. Volatile Memory
Volatile memory requires a constant power supply in order to retain stored data. Common examples of volatile memory include static read-only memory (SRAM) and dynamic read-only memory (DRAM). To overcome their power limitations, computer vendors sometimes add battery power to volatile memory devices to store temporarily in the event that power is suddenly cut off.
In general, volatile memory loses data when the machine is shut down but is faster than non-volatile memory. NVM doesn’t need a battery or any other type of power to retain data but operates more slowly than volatile memory.
NVM vs. NVMe
There are two broad categories of non-volatile memory: non-volatile memory and non-volatile memory express (NVMe).
NVM is the most common type and first emerged in the 1940s in the form of physically punched tape and cards. NVMe is a modern host controller interface and storage protocol that came to market in 2010.
Run by a consortium of storage technology vendors called the NVM Host Controller Interface Work Group, NVMe is designed to speed up NME by increasing the data transfer rate between host systems and SSDs. NVMe aims for interoperability across different NVM formats, including 3D XPoint and NAND flash.
NVMe’s main advantage over other forms of NVM is its simpler execution. It needs less than half the number of central processing unit (CPU) instructions than other NVMs in common use. NVMe also offers lower latency and the potential for lower power consumption.
Non-Volatile Memory Applications
Non-volatile memory is commonly used to store data that end users access repeatedly, like operating systems, software applications, and documents. Non-volatile memory is also used in archival storage as it enables data to be held for long periods without electricity.
Smartphones and tablets also rely on flash NVM to store mobile device operating systems, popular apps for secure media streaming, photos, videos, and music files.
NVM Examples
Hard disks (HDDs) and solid-state drives (SSDs) are two of the most widely used types of non-volatile memory.
Other examples include:
- Erasable programmable ROM (EPROM).
- Ferroelectric RAM (FRAM).
- Other magnetic storage devices like magnetic tape and floppy disks.
- Optical disks.
- Punched tape and cards (an early form of computer storage).
Non-Volatile Memory Pros and Cons
- Data persistence, which is vital for modern computing as it allows operating systems, software applications, and user data to be stored safely even when no power supply is present
- Higher storage capacity
- NVM is less expensive per unit than volatile memory
- Typically executes read and write operations at a slower pace than volatile memory
- It is arguably less secure than volatile memory as anything stored in volatile memory disappears after a machine is turned off
- Some types of NVM like flash memory have a limited write cycle and may need to be replaced more frequently
The Bottom Line
Memory is one of the most basic components in computing, and today’s systems need two different types to operate quickly and efficiently: volatile memory and non volatile memory.
Volatile memory delivers data quickly for short-term use, while non-volatile memory, by definition, stores data pervasively so it can be reused again and again – even if the power is switched off.
What type of memory is non-volatile? Hard drives and solid-state drives are forms of NVM used to store boot instructions, operating systems, software applications, and user files.
