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Computer Memory and How It Works
All computers have memory.
Without it, we would just have a
device that does fixed
operations and it would be more
like a calculator. So what is
computer memory and how does it
work?
Technically, computer memory is
any form of electronic storage.
There are many types of memory
within a computer, all varying
in size due to cost. Because the
hard drive is the most cost
effective, it is the largest
portion of our system, enabling
us to have home PC’s. The most
expensive memory system within
our computer is the cache.
To put memory into very simple
terms, lets imagine that we are
turning on our home PC. When
your computer is turned on, the
first thing your system does is
load data from its ROM or
read-only memory. ROM is a type
of memory that is preloaded with
data and software that never
changes. ROM also stores your
computer’s initial start-up
instructions.
Once your computer loads data
from ROM, in then loads the
operating system from the hard
drive into the system’s RAM or
Random Access Memory. RAM can be
read and written to at any time.
Your computer’s CPU (central
processing unit) commands the
RAM. The hard drive, operating
system and CPU all work as a
team.
Once you open an application, it
is loaded into RAM. To conserve
RAM usage, many applications
load only the essential parts of
the program initially and then
load other pieces as needed.
When you save a file and close
the application, the file is
written to the specified storage
device and then it and the
application are purged from the
RAM.
RAM serves as temporary storage,
which holds information every
time something is loaded or
opened. Keeping it temporary
allows the CPU to access it more
easily. The CPU requests the
data from RAM, processes it and
then writes new data back to RAM
in a continuous cycle, often
millions of times every second.
Another type of storage that is
not accessible by the CPU is
called secondary storage. The
computer uses input/output
channels to access secondary
storage and stores information
using an intermediate area in
primary storage. Hard disks are
usually used as secondary
storage because of their
affordability. The down side is
that it takes a computer a few
thousandths of a second or
millisecond to access a byte of
information stored on a hard
drive. This sounds fast until
you see that it takes RAM a
thousand-millionth of a second
or a nanosecond to transfer the
same amount of information. This
makes hard disks a million times
slower than RAM.
Other secondary storage devices
such as CD and DVD’s and flash
memory, have an even longer
access time than hard disks.
Because of the cost and speed,
most computers will store
information in the primary
memory and then move the least
used information to secondary
storage devices, retrieving them
later when they are needed. As
more of these retrievals from
slower secondary storage are
needed, the slower your system
becomes.
Higher end computers, those used
by specialty companies, often
have systems with more RAM or
sophisticated systems to help
them maintain large amounts of
data without overburdening their
systems.
For most individuals or even
companies, keeping up with the
needed amount of memory can be
daunting. Each year, the
software we use and become
dependent upon along with the
applications we enjoy, require
more and more storage space.
Transferring information from
old computers to new can be
expensive and for some large
companies almost cost
prohibitive. Using third party
data storage companies in
archiving your information helps
your systems not get bogged down
while safely retaining your
information. And for many
companies, store critical
accounting information use third
party companies is the law.
What is the future for computer
memory and storage? All we know
is that it will only get bigger
and bigger and that our
computer’s as well as ourselves
depend on it.
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Annie
