Difference between
Memories
TIME STORAGECAPACIT COST/BIT OF STORAGE
Y
PRIMARY FASTER SMALLER HIGH
MEMORY
SECONDARY SLOWER HIGHER LOW
MEMORY
That is, Primary memory (i.e. RAM, ROM etc.) have faster access time,
smaller storage
capacity, and higher cost per bit of storage, as compared to secondary
memory.
Based on access time, storage capacity and cost/bit storage, the memory
devices (such as
RAM, ROM, Hard-disk, Floppy disk, Magnetic disk, Magnetic Tape, CD-ROM,
and
DVD etc.) can be categorized into three kinds of memory systems:
Semiconductor memory such as RAM, ROM etc
Magnetic memory such as Hard-disk, Floppy disk, and Magnetic tapes
Optical memory such as CD-ROM, DVD etc
A Central Processing Unit (CPU) in a computer system is an extremely fast
device as
compared to the main memory, but it can not work on its own. It depends on
the main
memory that sends data and instruction when required for processing.
, In other words, we can say that even memories with smaller size (i.e. primary
memory)
have very high access time (time taken by CPU to access a location in
memory), which
reduces the overall speed of a computer.
Computer memory can also be categorized on the basis of Volatile and Non-
Volatile
characteristics. Non-volatile Memory is a type of computer memory which
can retain the
stored information even if the power is shut down. Examples of Non-Volatile
Memory
are Read-only memory (ROM), flash memory, optical discs etc. On the other
hand, a
Volatile memory loses its content when the power goes off. Random Access
Memory
(RAM), which is the most common form of Primary Storage, is a type of
volatile
memory. When the computer is shut down, everything contained in RAM is
lost.
To reduce the idle time of the CPU and increase the speed of processing, a
fast memory
can be used. This can be done by using a large size of main memory. But the
cost of main
memories of relatively large size is still very high. To reduce the cost of a large
sized
memory, a special type of high speed memory, known as cache memory can
be used in
between the CPU and the main memory (as shown in Figure 3.2). Thus the
cost versus
Memories
TIME STORAGECAPACIT COST/BIT OF STORAGE
Y
PRIMARY FASTER SMALLER HIGH
MEMORY
SECONDARY SLOWER HIGHER LOW
MEMORY
That is, Primary memory (i.e. RAM, ROM etc.) have faster access time,
smaller storage
capacity, and higher cost per bit of storage, as compared to secondary
memory.
Based on access time, storage capacity and cost/bit storage, the memory
devices (such as
RAM, ROM, Hard-disk, Floppy disk, Magnetic disk, Magnetic Tape, CD-ROM,
and
DVD etc.) can be categorized into three kinds of memory systems:
Semiconductor memory such as RAM, ROM etc
Magnetic memory such as Hard-disk, Floppy disk, and Magnetic tapes
Optical memory such as CD-ROM, DVD etc
A Central Processing Unit (CPU) in a computer system is an extremely fast
device as
compared to the main memory, but it can not work on its own. It depends on
the main
memory that sends data and instruction when required for processing.
, In other words, we can say that even memories with smaller size (i.e. primary
memory)
have very high access time (time taken by CPU to access a location in
memory), which
reduces the overall speed of a computer.
Computer memory can also be categorized on the basis of Volatile and Non-
Volatile
characteristics. Non-volatile Memory is a type of computer memory which
can retain the
stored information even if the power is shut down. Examples of Non-Volatile
Memory
are Read-only memory (ROM), flash memory, optical discs etc. On the other
hand, a
Volatile memory loses its content when the power goes off. Random Access
Memory
(RAM), which is the most common form of Primary Storage, is a type of
volatile
memory. When the computer is shut down, everything contained in RAM is
lost.
To reduce the idle time of the CPU and increase the speed of processing, a
fast memory
can be used. This can be done by using a large size of main memory. But the
cost of main
memories of relatively large size is still very high. To reduce the cost of a large
sized
memory, a special type of high speed memory, known as cache memory can
be used in
between the CPU and the main memory (as shown in Figure 3.2). Thus the
cost versus
