Difference between Volatile Memory and Non-Volatile Memory

Volatile memory and non-volatile memory are two distinct types of computer memory with significant differences in terms of their functionality and data storage characteristics. Volatile memory is used for temporary storage and loses its data when the power is removed, while non-volatile memory is used for permanent or long-term storage and preserves data even when the power is off.

What is Volatile Memory?

Volatile memory is a type of computer memory that requires a continuous power supply to retain data. This means that when the power is turned off or interrupted, the data stored in volatile memory is lost. The primary purpose of volatile memory is to provide fast and temporary storage for data that is actively being processed by the computer's central processing unit (CPU). The most common example of volatile memory is Random Access Memory (RAM). Volatile memory offers high-speed data access and allows for quick read and write operations. However, its volatile nature means that it cannot retain data once the power supply is cut off. Characteristics of the volatile memory are as follows:

  • Data Storage: Volatile memory stores data temporarily while the computer is running. It is used to hold the currently executing programs, operating system data, and data being actively processed by the CPU.

  • Speed: Volatile memory provides fast access to data, making it suitable for tasks that require rapid read and write operations. It enables quick data retrieval and efficient execution of instructions.

  • Capacity: Volatile memory has a relatively smaller capacity compared to non-volatile memory. RAM sizes can range from a few gigabytes to several terabytes, depending on the system's configuration.

  • Data Persistence: Volatile memory does not retain data when the power supply is interrupted or turned off. It needs to be refreshed constantly to maintain the stored information.

What is Non-volatile Memory?

Non-volatile memory refers to a type of computer memory that can retain data even when the power supply is disconnected. It retains information for an extended period or until explicitly modified or erased. The most common examples of non-volatile memory include hard disk drives (HDDs), solid-state drives (SSDs), flash memory, and read-only memory (ROM). Here are some key characteristics of non-volatile memory:

  • Data Storage: Non-volatile memory is used for long-term storage of data, such as the operating system, applications, user files, and other permanent data. It allows data to persist even after the system is powered off or restarted.

  • Speed: Non-volatile memory generally has slower read and write speeds compared to volatile memory. However, advancements in technology have led to faster non-volatile memory solutions such as solid-state drives (SSDs) that offer comparable speeds to volatile memory.

  • Capacity: Non-volatile memory has a larger capacity compared to volatile memory. Hard drives and solid-state drives are available in capacities ranging from gigabytes to multiple terabytes, making them suitable for storing large amounts of data.

  • Data Persistence: Non-volatile memory retains data even in the absence of power. This characteristic makes it ideal for long-term storage and ensures that the data remains intact and accessible across power cycles.

  • Cost: Generally, volatile memory is more affordable compared to non-volatile memory. This is because volatile memory is typically implemented using integrated circuits that are easier and cheaper to produce. Non-volatile memory, especially certain types like solid-state drives, tends to be more expensive due to the complex technology involved in storing data persistently

Difference between Volatile Memory and Non-Volatile Memory

The following table highlights the major differences between Volatile and Non-volatile memory:


Volatile Memory

Non-Volatile Memory

Data Retention

Requires continuous power supply to retain data.

Retains data even when power is turned off.

Data Storage

Temporary storage of data.

Permanent storage of data.


Faster access and data retrieval.

Slower access and data retrieval compared to volatile memory.


RAM (Random Access Memory), cache memory.

ROM (Read-Only Memory), flash memory, hard disk drives (HDD), solid-state drives (SSD).


Mainly used for short-term storage and quick access to data.

Used for long-term storage, firmware, and system software.

Data Integrity

Data is lost when power is interrupted or turned off.

Data is preserved even in the absence of power.

Write Endurance

Can be written multiple times without limitations.

Limited write endurance, but varies depending on the technology.


Generally more expensive compared to non-volatile memory.

Generally less expensive compared to volatile memory.


Highly volatile, meaning data is lost when power is lost or turned off.

Non-volatile, meaning data is retained even when power is lost or turned off.

Power Consumption

Requires constant power supply to maintain data.

Does not require power to retain data.


The key difference between volatile memory and non-volatile memory lies in their ability to retain data when the power is removed. Volatile memory is temporary, fast, and used for active data storage, while non-volatile memory is persistent, slower, and employed for long-term data storage even without power. Each type serves its own purpose in computer systems, with volatile memory providing temporary working space and non-volatile memory ensuring data integrity and long-term storage.

Updated on: 12-Jul-2023

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