What Is
Fragmentation, and What
Causes It?
To understand why
fragmentation occurs, we
must first gain a brief
understanding of how a
computer stores information.
Think of your hard drive as
a large grid full of
thousands of different
blocks. Each one of these
blocks has a number assigned
to it by your file system
(known as an address), for
organizational purposes.
When your computer stores
information on your hard
drive, it requests the
required amount of free
blocks from your file
system, and the file system
returns the address to each
of these blocks. In an ideal
world, these blocks would
always be right next to each
other, and read at the same
time you want to retrieve
that file.
Sometimes, however, the
file may be stored at
several different locations
scattered throughout your
file system. Therefore,
instead of reading a set of
blocks in order, it will
read a few blocks, then have
to look for the next set of
blocks, read them, and look
for the next set.
The same thing applies to
writing files as well.
Because your hard drive can
only read one block at a
time, you can probably
understand why this would
slow down your disc read and
write speeds, thus slowing
down your PC. When this
happens, it is time for a
defrag.
