<s>
In	O
the	O
history	O
of	O
optical	B-Device
storage	I-Device
media	I-Device
there	O
have	O
been	O
and	O
there	O
are	O
different	O
optical	B-Device
disc	I-Device
formats	O
with	O
different	O
data	O
writing/reading	O
speeds	O
.	O
</s>
<s>
Original	O
CD-ROM	B-Device
drives	O
could	O
read	O
data	O
at	O
about	O
150	O
kB/s	O
,	O
1×	O
constant	B-Device
angular	I-Device
velocity	I-Device
(	O
CAV	O
)	O
,	O
the	O
same	O
speed	O
of	O
compact	O
disc	O
players	O
without	O
buffering	O
.	O
</s>
<s>
As	O
faster	O
drives	O
were	O
released	O
,	O
the	O
write	O
speeds	O
and	O
read	O
speeds	O
for	O
optical	B-Device
discs	I-Device
were	O
multiplied	O
by	O
manufacturers	O
,	O
far	O
exceeding	O
the	O
drive	O
speeds	O
originally	O
released	O
onto	O
the	O
market	O
.	O
</s>
<s>
For	O
example	O
,	O
writing	O
to	O
a	O
CD	B-Device
at	O
8×	O
will	O
be	O
twice	O
as	O
fast	O
as	O
writing	O
onto	O
a	O
disc	O
at	O
4×	O
.	O
</s>
<s>
If	O
the	O
disc	O
spins	O
at	O
a	O
constant	B-Device
angular	I-Device
velocity	I-Device
,	O
the	O
linear	B-Device
velocity	I-Device
is	O
2.4	O
times	O
higher	O
at	O
the	O
outer	O
edge	O
.	O
</s>
<s>
It	O
is	O
important	O
to	O
note	O
that	O
the	O
speed	O
of	O
writing	O
a	O
DVD	O
at	O
1×	O
(	O
)	O
is	O
approximately	O
9	O
times	O
as	O
fast	O
as	O
writing	O
a	O
CD	B-Device
at	O
1×	O
(	O
)	O
.	O
</s>
<s>
For	O
CDs	B-Device
,	O
the	O
1×	O
writing	O
speed	O
is	O
equivalent	O
to	O
the	O
1×	O
reading	O
speed	O
,	O
which	O
in	O
turn	O
represents	O
the	O
speed	O
at	O
which	O
a	O
piece	O
of	O
media	O
can	O
be	O
read	O
in	O
its	O
entirety	O
,	O
74	B-Device
minutes	I-Device
.	O
</s>
<s>
Those	O
74	B-Device
minutes	I-Device
come	O
from	O
the	O
maximum	O
playtime	O
that	O
the	O
Red	O
Book	O
(	O
audio	O
CD	B-Device
standard	O
)	O
specifies	O
for	O
a	O
digital	O
audio	O
CD	B-Device
(	O
CD-DA	O
)	O
;	O
although	O
now	O
,	O
most	O
recordable	O
CDs	B-Device
can	O
hold	O
80minutes	O
worth	O
of	O
data	O
.	O
</s>
<s>
Since	O
their	O
debut	O
on	O
various	O
optical	B-Device
storage	I-Device
media	I-Device
during	O
the	O
fifth	B-Application
up	O
to	O
before	O
the	O
seventh	B-Application
generation	I-Application
(	O
1994	O
–	O
2005	O
)	O
,	O
the	O
size	O
of	O
data	O
in	O
video	O
games	O
did	O
not	O
require	O
an	O
installation	O
on	O
a	O
non-optical	O
support	O
and	O
the	O
reading	O
speed	O
of	O
optical	O
drives	O
was	O
enough	O
so	O
that	O
data	O
could	O
be	O
read	O
directly	O
from	O
optical	B-Device
discs	I-Device
.	O
</s>
<s>
As	O
seventh	B-Application
generation	I-Application
video	O
games	O
caught	O
on	O
,	O
the	O
size	O
of	O
data	O
,	O
higher	O
quality	O
texture	O
mapping	O
etc.	O
,	O
required	O
in	O
turn	O
a	O
higher	O
stream	B-Architecture
of	I-Architecture
data	I-Architecture
coming	O
out	O
of	O
optical	B-Device
storage	I-Device
media	I-Device
.	O
</s>
<s>
Video	O
games	O
for	O
PlayStation	B-Operating_System
3	I-Operating_System
were	O
stored	O
on	O
single-layer	O
Blu-ray	O
which	O
has	O
a	O
higher	O
transfer	O
rate	O
by	O
default	O
but	O
the	O
console	O
's	O
optical	O
drive	O
speed	O
multiplier	O
was	O
set	O
at	O
2×	O
(	O
9	O
MB/s	O
)	O
.	O
</s>
<s>
On	O
Xbox	B-Operating_System
360	I-Operating_System
,	O
video	O
games	O
were	O
stored	O
on	O
common	O
dual-layer	O
8.5	O
GB	O
DVDs	O
but	O
with	O
the	O
console	O
's	O
12×	O
drive	O
speed	O
multiplier	O
(	O
16.5	O
MB/s	O
)	O
,	O
Xbox	B-Operating_System
360	I-Operating_System
could	O
achieve	O
up	O
to	O
85%	O
faster	O
data	O
transfer	O
rate	O
than	O
PlayStation	B-Operating_System
3	I-Operating_System
.	O
</s>
<s>
Slower	O
transfer	O
rate	O
on	O
PlayStation	B-Operating_System
3	I-Operating_System
led	O
many	O
multi-platform	O
developers	O
for	O
a	O
mandatory	O
installation	O
of	O
a	O
portion	O
of	O
the	O
disc	O
's	O
content	O
on	O
the	O
console	O
's	O
hard	B-Device
disk	I-Device
drive	I-Device
(	O
HDD	O
)	O
in	O
order	O
to	O
offset	O
problems	O
such	O
as	O
longer	O
loading	O
times	O
.	O
</s>
<s>
Xbox	B-Operating_System
360	I-Operating_System
could	O
install	O
games	O
entirely	O
on	O
HDD	O
and	O
potentially	O
improve	O
loading	O
times	O
but	O
this	O
was	O
never	O
mandatory	O
.	O
</s>
<s>
Optical	B-Device
discs	I-Device
were	O
still	O
required	O
to	O
boot	O
games	O
.	O
</s>
<s>
Seventh	B-Application
generation	I-Application
video	O
games	O
rarely	O
filled	O
the	O
space	O
of	O
an	O
entire	O
single-layer	O
Blu-ray	O
disc	O
(	O
25	O
GB	O
)	O
or	O
required	O
two	O
or	O
more	O
DVDs	O
on	O
Xbox	B-Operating_System
360	I-Operating_System
.	O
</s>
<s>
From	O
the	O
eighth	B-Application
generation	I-Application
onward	O
,	O
full	O
1080p	O
high-definition	O
graphics	O
,	O
higher	O
quality	O
textures	O
,	O
further	O
required	O
a	O
higher	O
stream	B-Architecture
of	I-Architecture
data	I-Architecture
and	O
as	O
such	O
Blu-ray	O
optical	O
drives	O
 '	O
reading	O
speed	O
at	O
6×	O
(	O
27	O
MB/s	O
)	O
soon	O
proved	O
to	O
be	O
insufficient	O
.	O
</s>
<s>
For	O
this	O
reason	O
,	O
consoles	O
like	O
PlayStation	B-Operating_System
4	I-Operating_System
force-install	O
video	O
games	O
entirely	O
on	O
HDD	O
,	O
which	O
allows	O
a	O
higher	O
stream	B-Architecture
of	I-Architecture
data	I-Architecture
.	O
</s>
<s>
Like	O
it	O
was	O
for	O
Xbox	B-Operating_System
360	I-Operating_System
,	O
optical	B-Device
discs	I-Device
are	O
still	O
required	O
to	O
boot	O
games	O
.	O
</s>
<s>
Almost	O
all	O
modern	O
CD/DVD	B-Application
-burning	I-Application
software	O
supports	O
a	O
selection	O
of	O
speeds	O
at	O
which	O
the	O
writable	O
disc	O
can	O
be	O
written	O
.	O
</s>
<s>
However	O
,	O
the	O
option	O
a	O
user	O
chooses	O
only	O
defines	O
the	O
theoretical	O
maximum	O
of	O
disc	B-Application
burning	I-Application
process	O
.	O
</s>
<s>
Resources	O
available	O
to	O
the	O
program	O
:	O
Reading	O
or	O
writing	O
data	O
on	O
a	O
disc	O
consumes	O
moderate	O
to	O
high	O
level	O
of	O
system	O
resources	O
(	O
including	O
memory	B-General_Concept
and	O
CPU	B-Device
resources	O
)	O
,	O
and	O
running	O
other	O
programs	O
at	O
the	O
same	O
time	O
may	O
force	O
the	O
CD/DVD	O
drive	O
to	O
choose	O
a	O
lower	O
speed	O
automatically	O
,	O
to	O
accommodate	O
the	O
available	O
resources	O
.	O
</s>
<s>
Disc	O
quality	O
:	O
optical	B-Device
disc	I-Device
recorders	O
detect	O
the	O
available	O
speed	O
options	O
based	O
on	O
the	O
data	O
which	O
is	O
available	O
on	O
the	O
disc	O
itself	O
.	O
</s>
<s>
CD	B-Device
drives	O
and	O
many	O
early	O
DVD	O
drives	O
stored	O
data	O
with	O
constant	B-Device
linear	I-Device
velocity	I-Device
,	O
so	O
that	O
the	O
data	O
rate	O
remained	O
the	O
same	O
regardless	O
of	O
the	O
position	O
of	O
the	O
optical	O
head	O
.	O
</s>
<s>
Modern	O
DVD	O
drives	O
use	O
constant	B-Device
angular	I-Device
velocity	I-Device
to	O
allow	O
transferring	O
data	O
at	O
the	O
highest	O
supported	O
physical	O
rotation	O
speed	O
and/or	O
random	B-General_Concept
access	I-General_Concept
without	O
needing	O
to	O
adjust	O
the	O
physical	O
rotation	O
speed	O
on	O
every	O
jump	O
,	O
and	O
Zoned	O
Constant	B-Device
Linear	I-Device
Velocity	I-Device
for	O
writing	O
reliably	O
with	O
different	O
data	O
rates	O
in	O
different	O
zones	O
.	O
</s>
