difference between primary and secondary storage

Difference Between Primary and Secondary Memory

PRIMARY MEMORY

1. Primary memory is also known as Main memory or Internal memory
2. In primary memory, data is directly accessed by the processing unit.
3. Semi conductor chips are used to store information in primary memory.
4. Information stored is temporary and it can be lost when there is a sudden power cut.
5. Data operated and stored in uniform manner.
6. Primary memory devices are more expensive than secondary storage devices.
7. Nature of Parts of Primary memory varies. RAM- volatile in nature. ROM- Non-volatile
8. It is very fast in interacting with micro processor.
9. Primary memory has limited storage capacity.
10. Examples: RAM, ROM, Cache memory, PROM, EPROM, Registers etc

SECONDARY MEMORY

1. Secondary memory is also known as External memory or Auxiliary memory
2. In secondary memory, data is first transferred to main memory and then routed to processing unit.
3. Magnetic disk, optical disks are used to store information in secondary memory.
4. Information stored is permanent unless one deletes it intentionally.
5. Data stored is not uniform in secondary memory.
6. Secondary memory devices are less expensive when compare to primary memory devices.
7. It’s always Non-volatile in nature.
8. It is little slow in interacting with micro processor.
9. Whereas secondary memory can store bulk amounts of data in a single unit.
10. Examples: Magnetic Tapes, Optical Disc, Floppy Disks, Flash memory [USB drives], Paper Tape, Punched cards etc
11. Comparison Chart

BASIS FOR COMPARISON	PRIMARY MEMORY	SECONDARY MEMORY
Basic	Primary memory is directly accessible by Processor/CPU.	Secondary memory is not directly accessible by CPU.
Altered Name	Main memory.	Auxiliary memory.
Data	Instructions or data to be currently executed are copied to main memory.	Data to be permanently stored is kept in secondary memory.
Volatility	Primary memory is usually volatile.	Secondary memory is non-volatile.
Formation	Primary memories are made of semiconductors.	Secondary memories are made of magnetic and optical material.
Access Speed	Accessing data from primary memory is faster.	Accessing data from secondary memory is slower.
Access	Primary memory is accessed by the data bus.	Secondary memory is accessed by input-output channels.
Size	The computer has a small primary memory.	The computer has a larger secondary memory.
Expense	Primary memory is costlier than secondary memory.	Secondary memory is cheaper than primary memory
Memory	Primary memory is an internal memory.	Secondary memory is an external memory.