In
this tutorial, you will learn
· What
is Memory?
· What
is Primary Memory?
· RAM
(Random Access Memory)
· ROM
(Read Only Memory)
· What
is Secondary Memory?
· Types
of Secondary memory
· Characteristic
of Primary Memory
· Characteristic
Secondary Memory
What is Memory?
Memory is very much like our brain as it is used to
store data and instructions. Computer memory is the storage space where data is
to be processed, and instructions needed for processing are stored. The memory
is divided into a large number of smaller portions called the cell. Every cell/
location has a unique address and a size.
Two
Types of Memories Are:
1. Primary
Memory
2. Secondary
Memory
What is Primary Memory?
Primary memory is the main memory of the computer
system. Accessing data from primary memory is faster because it is an internal
memory of the computer. The primary memory is most volatile which means data in
primary memory does not exist if it is not saved when a power failure occurs.
The primary memory is a semiconductor memory. It is
costlier compared with secondary memory. The capacity of primary memory is very
much limited and is always smaller compares to secondary memory.
Two types of Primary Memory are:
ü RAM
ü ROM
KEY DIFFERENCE BETWEEN PRIMARY AND
SECONDARY MEMORY
1. Primary
memory is also called internal memory whereas Secondary memory is also known as
a Backup memory or Auxiliary memory.
2. Primary
memory can be accessed by the data bus whereas Secondary memory is accessed by
I/O channels.
3. Primary
memory data is directly accessed by the processing unit whereas Secondary
memory data cannot be accessed directly by the processor.
4. Primary
memory is costlier than secondary memory whereas Secondary memory is cheaper
compared to primary memory.
5. Primary
memory is both volatile & nonvolatile whereas Secondary memory is always a
non-volatile memory.
·
RAM (Random Access Memory)
Random access memory which is also known as RAM is generally known as a main memory of the computer system. It is called temporary
memory or cache memory. The information stored in this type of memory is lost
when the power supply to the PC or laptop is switched off.
Types of RAM
ü DRAM: DRAM stands for Dynamic RAM, and it is the most
common type of RAM used in computers. The oldest type is known as Single Data
Rate (SDR) DRAM, but newer computers use faster Dual Data Rate (DDR) DRAM. DDR
comes in several versions including DDR2, DDR3, and DDR4, which offer better
performance and are more energy efficient than DDR. However different versions
are incompatible, so it is not possible to mix DDR2 with DDR3 DRAM in a
computer system. DRAM
consists of a transistor and a capacitor in each cell.
ü SRAM: SRAM stands for Static RAM, and it is a particular
type of RAM which is faster than DRAM, but more expensive and bulker, having
six transistors in each cell.
·
ROM (Read Only Memory)
It stands for Read Only Memory. ROM is a permanent
type of memory. Its content is not lost when the power supply is switched off.
The computer manufacturer decides the information of ROM, and it is permanently
stored at the time of manufacturing which can not be overwritten by the user.
What is Secondary Memory?
1.
Secondary
memory by contrast, is usually physically located within a separate storage
device, such as a hard disk
drive or solid state drive (SSD), which is connected to the computer system either
directly or over a network.
All secondary storage devices which are capable of
storing high volume data is referred to secondary memory. It’s slower than
primary memory. However, it can save a substantial amount of data, in the range
of gigabytes to terabytes. This memory is also called backup storage or
mass storage media.
Examples
of Secondary memories
· CD.
· DVD.
· Blue
Ray.
· USB
drives: It is one of the most popular types of secondary storage device
available in the market. USB drives are removable, rewritable and are physically
very small. The capacity of USB drives is also increasing significantly as
today 1TB pen drive is also available in the market.
Characteristic
of Primary Memory
· The
computer can’t run without primary memory.
· It
is known as the main memory.
· You
can lose data in case power is switched off.
· It
is also known as volatile memory.
· It
is a working memory of the computer.
· Primary
memory is faster compares to secondary memory.
Characteristic
Secondary Memory
· These
are magnetic and optical memories.
· Secondary
memory is known as a backup memory.
· It
is a non-volatile type of memory.
· Data
is stored permanently even when the power of the computer is switched off.
· It
helps store data in a computer.
· The
machine can run without secondary memory.
· Slower
than primary memory.
Uses of Computer Memory
1.
It is used to
store data that the CPU needs imminently so that it does not have to wait for
it to be delivered.
Summary
- Computer memory is the storage
space where data is to be processed, and instructions needed for
processing are stored
- Two types of memories are 1)
Primary Memory, 2) Secondary Memory.
- Primary memory is the main
memory of the computer system. Accessing data from primary memory is
faster because it is an internal memory of the computer.
- All secondary storage devices
which are capable of storing high volume data is referred to as secondary
memory
- Types of Primary Memory 1) RAM,
2) ROM
- Types of Secondary Memory 1)
Hard Drive, 2) SSD, 3) Flash, 4) Optical Drive, 5) USD Drive, 3) Magnetic
Tapes
- The computer can't run without
primary memory. You can lose data in case power is switched off
- Data is stored permanently in
Secondary Memory even when the power of the computer is switched off
- Primary memory is expensive and
is available in limited in size in a computer.
- Secondary memory is cheaper
compared to primary memory.
References
3.
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