<s>
In	O
computer	B-General_Concept
storage	I-General_Concept
,	O
zone	B-Architecture
bit	I-Architecture
recording	I-Architecture
(	O
ZBR	O
)	O
is	O
a	O
method	O
used	O
by	O
disk	B-Device
drives	I-Device
to	O
optimise	O
the	O
tracks	O
for	O
increased	O
data	O
capacity	O
.	O
</s>
<s>
It	O
does	O
this	O
by	O
placing	O
more	O
sectors	B-Application
per	O
zone	O
on	O
outer	O
tracks	O
than	O
on	O
inner	O
tracks	O
.	O
</s>
<s>
This	O
contrasts	O
with	O
other	O
approaches	O
,	O
such	O
as	O
constant	B-Device
angular	I-Device
velocity	I-Device
(	O
CAV	O
)	O
-drives	O
,	O
where	O
the	O
number	O
of	O
sectors	B-Application
per	O
track	B-Device
are	O
the	O
same	O
.	O
</s>
<s>
On	O
a	O
disk	B-Device
consisting	O
of	O
roughly	O
concentric	O
tracks	O
–	O
whether	O
realized	O
as	O
separate	O
circular	O
tracks	O
or	O
as	O
a	O
single	O
spiral	O
track	B-Device
–	O
the	O
physical	O
track	B-Device
length	O
(	O
circumference	O
)	O
is	O
increased	O
as	O
it	O
gets	O
farther	O
from	O
the	O
centre	O
hub	O
.	O
</s>
<s>
The	O
packing	O
of	O
the	O
rest	O
of	O
the	O
disks	B-Device
is	O
changed	O
depending	O
on	O
the	O
type	O
of	O
disk	B-Device
.	O
</s>
<s>
Storing	O
more	O
bits	O
per	O
track	B-Device
equates	O
to	O
achieving	O
a	O
higher	O
total	O
data	O
capacity	O
on	O
the	O
same	O
disk	B-Device
area	O
.	O
</s>
<s>
However	O
,	O
ZBR	O
influences	O
other	O
performance	O
characteristics	O
of	O
the	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
Since	O
both	O
hard	B-Device
disks	I-Device
and	O
floppy	B-Device
disks	I-Device
typically	O
number	O
their	O
tracks	O
beginning	O
at	O
the	O
outer	O
edge	O
and	O
continuing	O
inward	O
,	O
and	O
since	O
operating	O
systems	O
typically	O
fill	O
the	O
lowest-numbered	O
tracks	O
first	O
,	O
this	O
is	O
where	O
the	O
operating	O
system	O
typically	O
stores	O
its	O
own	O
files	O
during	O
its	O
initial	O
installation	O
onto	O
an	O
empty	O
drive	O
.	O
</s>
<s>
Testing	O
disk	B-Device
drives	I-Device
when	O
they	O
are	O
new	O
or	O
empty	O
after	O
defragmenting	O
them	O
with	O
some	O
benchmarking	O
applications	O
will	O
often	O
show	O
their	O
highest	O
performance	O
.	O
</s>
<s>
After	O
some	O
time	O
,	O
when	O
more	O
data	O
are	O
stored	O
in	O
the	O
inner	O
tracks	O
,	O
the	O
average	O
data	O
transfer	O
rate	O
will	O
drop	O
,	O
because	O
the	O
transfer	O
rate	O
in	O
the	O
inner	O
zones	O
is	O
slower	O
;	O
this	O
,	O
combined	O
with	O
the	O
head	O
's	O
longer	O
stroke	O
and	O
possible	O
fragmentation	B-Architecture
,	O
may	O
give	O
the	O
impression	O
of	O
the	O
disk	B-Device
drive	I-Device
slowing	O
down	O
over	O
time	O
.	O
</s>
<s>
Some	O
other	O
ZBR	O
drives	O
,	O
such	O
as	O
the	O
800	O
kilobyte	O
3.5	B-Device
"	I-Device
floppy	B-Device
drives	I-Device
in	O
the	O
Apple	B-Device
IIGS	I-Device
and	O
older	O
Macintosh	B-Device
computers	I-Device
,	O
do	O
n't	O
change	O
the	O
data	O
rate	O
but	O
rather	O
spin	O
the	O
medium	O
slower	O
when	O
reading	O
or	O
writing	O
outer	O
tracks	O
,	O
thus	O
approximating	O
the	O
performance	O
of	O
constant	B-Device
linear	I-Device
velocity	I-Device
drives	O
.	O
</s>
