Abu Zar Mishwani
Computers have two main kinds of hardware-based memory: volatile and non-volatile. The key distinction lies in what happens to the memory when the computer is turned off.
In this article, we’ll explore the differences between two types of computer memory: volatile and nonvolatile.
In simple terms, the main difference between volatile memory and non-volatile memory is that:
Volatile memory loses its data when power is turned off (e.g., RAM), while non-volatile memory retains data even without power (e.g., ROM, flash drives).
Now, let’s explore each type of memory in more detail.
What is Volatile Memory?
Volatile memory is a type of computer memory that temporarily stores data as long as the computer is powered on. It loses its stored information when the power is turned off or interrupted.
RAM (Random Access Memory) is a common example of volatile memory.
When you run a program or open a file, the computer loads the relevant data into RAM to provide quick access for the processor. However, the key characteristic of RAM is that it is volatile, meaning it doesn’t retain its contents when the power is turned off. Once you shut down your computer, the data stored in RAM is lost.
For example, you’re working on a document in Microsoft Word. As you edit the document, the changes you make are temporarily stored in the computer’s RAM for quick access by the processor. However, if you turn off your computer without saving the document to the hard disk drive (a non-volatile storage), all the recent changes made in the Word program would be lost because the RAM is volatile and doesn’t retain data without power.
What is Non-Volatile Memory?
Non-volatile memory is a type of computer memory that retains its stored information even when the power is turned off. Non-volatile memory preserves data over extended periods without the need for continuous power.
A hard disk drive (HDD) is a common example of non-volatile memory. It’s a data storage device used in computers to permanently store and retrieve digital information. The data stored on a hard drive remains intact even when the computer is shut down.
Other common examples of non-volatile memory include ROM (Read-Only Memory), CDs, DVDs, Blu-ray Discs, and Flash Memory.
Difference Between Volatile and Non Volatile Memory
| Characteristic | Volatile Memory | Non-Volatile Memory |
|---|---|---|
| Data Retention | Loses data when power is off | Retains data even when power is off |
| Examples | RAM, Cache memory, Registers | Hard Disk Drives (HDD), SSD, Flash Memory, ROM |
| Main Use | Temporary storage for active processes, running programs | Permanent storage for files, programs, and the operating system |
| Speed | Faster access, but limited capacity | Slower access compared to RAM, but larger storage capacity |
| Volatility | Volatile – data is lost on power loss | Non-volatile – data persists through power cycles |
| Function | Stores data actively in use, facilitating quick access | Stores data persistently for long-term storage |
| Cost | Generally lower cost per unit of storage | Can be more expensive, especially for high-speed options like SSDs |
| Type of Memory Cells | Uses dynamic memory cells (e.g., dynamic RAM - DRAM) | Uses non-volatile memory cells (e.g., NAND flash for SSDs) |
| Energy Consumption | Requires continuous power to maintain data | Requires less power, as data is retained without continuous power |