Primary vs Secondary Memory: Difference and Comparison

In computers, memory is considered as one of the most essential parts. The device stores information in the computer for immediate use or later.

It can also be considered as the brain of the computer. Computer memory is basically of two types: primary and secondary.

Memory stores data inside itself for retrieval. Both primary and secondary memory have very different processes by which they save data.

The central processing unit then processes the data.

Key Takeaways

1. Primary memory, or RAM, is volatile, temporary storage used by the computer to store current data; secondary memory, or storage, is non-volatile, permanent storage used for long-term data storage and retrieval.
2. Primary memory is faster and more expensive than secondary memory; secondary memory is slower but has a larger capacity and is less expensive.
3. Primary memory is limited by the amount of RAM installed on the computer; secondary memory can be expanded with external hard drives or other storage devices.

Primary Memory vs. Secondary Memory

Primary memory, also known as main memory or random access memory (RAM), is a type of volatile memory directly accessible to the CPU. Secondary memory is a type of non-volatile memory used to store data for long-term use and is slower to access but is also much larger in capacity.

Primary and secondary memory are parts of the main memory unit in a computer that is used for storing and processing data.

Comparison Table

Parameters of Comparison	Primary Memory	Secondary Memory
Storage Validity	It is the main memory, and the data is stored temporarily.	It is the external memory, and the data is stored permanently.
Access	The CPU can directly access data.	The CPU cannot directly access the data.
Volatility	This type of memory is volatile, and the data is lost in case of a power failure.	This type of memory is non-volatile, and the data is stored even in case of power failure.
Storage Device	The data is stored inside very expensive semiconductor chips.	The data is stored in external hardware devices like hard drives, floppy disks, etc.
Division	It can be divided into cache and random access memory (RAM).	They have no such divisions and are permanent storage devices like CDs, DVDs, etc.
Speed	It is faster than the secondary memory.	It is relatively slower.
Data Stored	It saves the data that is currently being used by the computer.	It can save various kinds of data in several formats and huge sizes.

What is Primary Memory?

Primary memory is the kind of memory that can be accessed directly by the central processing unit. It includes several types of memory like RAM (Random Access Memory), ROM (Read Only Memory), and cache memory.

Primary memory is erased when the computer is shut off, and the data is not saved. The data transferred between the CPU and RAM is a hundred times faster than the speed of data transfer between the CPU and the hard drive.

Primary memory can also be called primary storage. Primary memory is expensive, and technology is constantly being used to develop and optimize it.

While RAM loses its memory, ROM can store program data permanently.

What is Secondary Memory?

Secondary memory refers to storage devices such as hard drives and pen drives. The storage device can either be removable or non-removable.

The data stored inside secondary memory devices is stored permanently. The storage capacity of secondary memory is also much larger than primary memory.

Operating systems, applications, and other files can be stored inside secondary memory devices. It can also be called external memory, as it is not always a part of the device.

Secondary memory devices are also slower and much cheaper than primary memory devices. Data stored inside the secondary storage device is organized in an accessible way and can show at what time, where, and what kind of file was stored.

Main Differences Between Primary Memory and Secondary Memory

1. Primary memory is the computer’s main memory, saving data temporarily. Secondary memory is the external memory that can be saved permanently.
2. The CPU can directly access data saved in primary memory, which is not the case in secondary memory.
3. Primary memory is lost in case of a power cut, while secondary memory remains saved. Hence primary memory is volatile and secondary memory is non-volatile.
4. Primary memory is stored in semiconductor chips, while secondary memory is stored in external hardware devices.
5. Primary memory is categorized into cache and random access memory, whereas secondary memory has no such categories.
6. Primary memory is faster than secondary memory.
7. Primary memory uses the computer’s current data, while secondary memory can save data in various formats that can be accessed at any time.

References

1. https://psycnet.apa.org/record/2006-23341-004
2. https://psycnet.apa.org/record/1974-04901-001
3. https://books.google.com/books?hl=en&lr=&id=yR8tq_YznMwC&oi=fnd&pg=PA378&dq=secondary+memory+of+computer&ots=1YbUH3R26l&sig=ZHcxYl28ZKaG0yZ2xhX7McSWdVs