<s>
A	O
motherboard	B-Device
(	O
also	O
called	O
mainboard	B-Device
,	O
main	O
circuit	O
board	O
,	O
MB	O
,	O
mboard	O
,	O
backplane	B-Architecture
board	O
,	O
base	O
board	O
,	O
system	B-Device
board	I-Device
,	O
mobo	O
;	O
or	O
in	O
Apple	O
computers	O
logic	B-Device
board	I-Device
)	O
is	O
the	O
main	O
printed	O
circuit	O
board	O
(	O
PCB	O
)	O
in	O
general-purpose	O
computers	O
and	O
other	O
expandable	O
systems	O
.	O
</s>
<s>
It	O
holds	O
and	O
allows	O
communication	O
between	O
many	O
of	O
the	O
crucial	O
electronic	O
components	O
of	O
a	O
system	O
,	O
such	O
as	O
the	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	B-Device
)	O
and	O
memory	B-General_Concept
,	O
and	O
provides	O
connectors	O
for	O
other	O
peripherals	B-Device
.	O
</s>
<s>
Unlike	O
a	O
backplane	B-Architecture
,	O
a	O
motherboard	B-Device
usually	O
contains	O
significant	O
sub-systems	O
,	O
such	O
as	O
the	O
central	O
processor	O
,	O
the	O
chipset	B-Device
's	O
input/output	B-General_Concept
and	O
memory	B-General_Concept
controllers	O
,	O
interface	B-Application
connectors	O
,	O
and	O
other	O
components	O
integrated	O
for	O
general	O
use	O
.	O
</s>
<s>
Motherboard	B-Device
means	O
specifically	O
a	O
PCB	O
with	O
expansion	O
capabilities	O
.	O
</s>
<s>
As	O
the	O
name	O
suggests	O
,	O
this	O
board	O
is	O
often	O
referred	O
to	O
as	O
the	O
"	O
mother	O
"	O
of	O
all	O
components	O
attached	O
to	O
it	O
,	O
which	O
often	O
include	O
peripherals	B-Device
,	O
interface	B-Application
cards	O
,	O
and	O
daughterboards	O
:	O
sound	B-Device
cards	I-Device
,	O
video	B-Device
cards	I-Device
,	O
network	B-Protocol
cards	I-Protocol
,	O
host	B-Architecture
bus	I-Architecture
adapters	I-Architecture
,	O
TV	B-Device
tuner	I-Device
cards	I-Device
,	O
IEEE	B-Protocol
1394	I-Protocol
cards	O
,	O
and	O
a	O
variety	O
of	O
other	O
custom	O
components	O
.	O
</s>
<s>
Similarly	O
,	O
the	O
term	O
mainboard	B-Device
describes	O
a	O
device	O
with	O
a	O
single	O
board	O
and	O
no	O
additional	O
expansions	O
or	O
capability	O
,	O
such	O
as	O
controlling	O
boards	O
in	O
laser	O
printers	O
,	O
television	O
sets	O
,	O
washing	O
machines	O
,	O
mobile	O
phones	O
,	O
and	O
other	O
embedded	B-Architecture
systems	I-Architecture
with	O
limited	O
expansion	O
abilities	O
.	O
</s>
<s>
Prior	O
to	O
the	O
invention	O
of	O
the	O
microprocessor	B-Architecture
,	O
the	O
digital	O
computer	O
consisted	O
of	O
multiple	O
printed	O
circuit	O
boards	O
in	O
a	O
card-cage	O
case	B-General_Concept
with	O
components	O
connected	O
by	O
a	O
backplane	B-Architecture
,	O
a	O
set	O
of	O
interconnected	O
sockets	O
.	O
</s>
<s>
The	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
(	O
CPU	B-Device
)	O
,	O
memory	B-General_Concept
,	O
and	O
peripherals	B-Device
were	O
housed	O
on	O
individually	O
printed	O
circuit	O
boards	O
,	O
which	O
were	O
plugged	O
into	O
the	O
backplane	B-Architecture
.	O
</s>
<s>
The	O
ubiquitous	O
S-100	B-Architecture
bus	I-Architecture
of	O
the	O
1970s	O
is	O
an	O
example	O
of	O
this	O
type	O
of	O
backplane	B-Architecture
system	I-Architecture
.	O
</s>
<s>
The	O
most	O
popular	O
computers	O
of	O
the	O
1980s	O
such	O
as	O
the	O
Apple	B-Device
II	I-Device
and	O
IBM	B-Device
PC	I-Device
had	O
published	O
schematic	O
diagrams	O
and	O
other	O
documentation	O
which	O
permitted	O
rapid	O
reverse-engineering	O
and	O
third-party	O
replacement	O
motherboards	B-Device
.	O
</s>
<s>
Usually	O
intended	O
for	O
building	O
new	O
computers	O
compatible	O
with	O
the	O
exemplars	O
,	O
many	O
motherboards	B-Device
offered	O
additional	O
performance	O
or	O
other	O
features	O
and	O
were	O
used	O
to	O
upgrade	O
the	O
manufacturer	O
's	O
original	O
equipment	O
.	O
</s>
<s>
During	O
the	O
late	O
1980s	O
and	O
early	O
1990s	O
,	O
it	O
became	O
economical	O
to	O
move	O
an	O
increasing	O
number	O
of	O
peripheral	O
functions	O
onto	O
the	O
motherboard	B-Device
.	O
</s>
<s>
In	O
the	O
late	O
1980s	O
,	O
personal	B-Device
computer	I-Device
motherboards	B-Device
began	O
to	O
include	O
single	O
ICs	O
(	O
also	O
called	O
Super	B-Device
I/O	I-Device
chips	O
)	O
capable	O
of	O
supporting	O
a	O
set	O
of	O
low-speed	O
peripherals	B-Device
:	O
PS/2	B-Protocol
keyboard	I-Protocol
and	O
mouse	B-Device
,	O
floppy	B-Device
disk	I-Device
drive	I-Device
,	O
serial	B-Protocol
ports	I-Protocol
,	O
and	O
parallel	B-Device
ports	I-Device
.	O
</s>
<s>
By	O
the	O
late	O
1990s	O
,	O
many	O
personal	B-Device
computer	I-Device
motherboards	B-Device
included	O
consumer-grade	O
embedded	O
audio	O
,	O
video	B-Device
,	O
storage	O
,	O
and	O
networking	O
functions	O
without	O
the	O
need	O
for	O
any	O
expansion	B-Device
cards	I-Device
at	O
all	O
;	O
higher-end	O
systems	O
for	O
3D	O
gaming	O
and	O
computer	O
graphics	O
typically	O
retained	O
only	O
the	O
graphics	B-Device
card	I-Device
as	O
a	O
separate	O
component	O
.	O
</s>
<s>
Business	O
PCs	B-Device
,	O
workstations	O
,	O
and	O
servers	O
were	O
more	O
likely	O
to	O
need	O
expansion	B-Device
cards	I-Device
,	O
either	O
for	O
more	O
robust	O
functions	O
,	O
or	O
for	O
higher	O
speeds	O
;	O
those	O
systems	O
often	O
had	O
fewer	O
embedded	O
components	O
.	O
</s>
<s>
Laptop	O
and	O
notebook	O
computers	O
that	O
were	O
developed	O
in	O
the	O
1990s	O
integrated	O
the	O
most	O
common	O
peripherals	B-Device
.	O
</s>
<s>
This	O
even	O
included	O
motherboards	B-Device
with	O
no	O
upgradeable	O
components	O
,	O
a	O
trend	O
that	O
would	O
continue	O
as	O
smaller	O
systems	O
were	O
introduced	O
after	O
the	O
turn	O
of	O
the	O
century	O
(	O
like	O
the	O
tablet	B-Device
computer	I-Device
and	O
the	O
netbook	B-Device
)	O
.	O
</s>
<s>
Memory	B-General_Concept
,	O
processors	O
,	O
network	B-Protocol
controllers	I-Protocol
,	O
power	O
source	O
,	O
and	O
storage	O
would	O
be	O
integrated	O
into	O
some	O
systems	O
.	O
</s>
<s>
A	O
motherboard	B-Device
provides	O
the	O
electrical	O
connections	O
by	O
which	O
the	O
other	O
components	O
of	O
the	O
system	O
communicate	O
.	O
</s>
<s>
Unlike	O
a	O
backplane	B-Architecture
,	O
it	O
also	O
contains	O
the	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
and	O
hosts	O
other	O
subsystems	O
and	O
devices	O
.	O
</s>
<s>
A	O
typical	O
desktop	B-Device
computer	I-Device
has	O
its	O
microprocessor	B-Architecture
,	O
main	O
memory	B-General_Concept
,	O
and	O
other	O
essential	O
components	O
connected	O
to	O
the	O
motherboard	B-Device
.	O
</s>
<s>
Other	O
components	O
such	O
as	O
external	B-Device
storage	I-Device
,	O
controllers	O
for	O
video	B-Device
display	O
and	O
sound	B-Device
,	O
and	O
peripheral	B-Device
devices	I-Device
may	O
be	O
attached	O
to	O
the	O
motherboard	B-Device
as	O
plug-in	O
cards	O
or	O
via	O
cables	O
;	O
in	O
modern	O
microcomputers	O
,	O
it	O
is	O
increasingly	O
common	O
to	O
integrate	O
some	O
of	O
these	O
peripherals	B-Device
into	O
the	O
motherboard	B-Device
itself	O
.	O
</s>
<s>
An	O
important	O
component	O
of	O
a	O
motherboard	B-Device
is	O
the	O
microprocessor	B-Architecture
's	O
supporting	O
chipset	B-Device
,	O
which	O
provides	O
the	O
supporting	O
interfaces	B-Application
between	O
the	O
CPU	B-Device
and	O
the	O
various	O
buses	B-General_Concept
and	O
external	O
components	O
.	O
</s>
<s>
This	O
chipset	B-Device
determines	O
,	O
to	O
an	O
extent	O
,	O
the	O
features	O
and	O
capabilities	O
of	O
the	O
motherboard	B-Device
.	O
</s>
<s>
Modern	O
motherboards	B-Device
include	O
:	O
</s>
<s>
CPU	B-General_Concept
sockets	I-General_Concept
(	O
or	O
CPU	B-General_Concept
slots	I-General_Concept
)	O
in	O
which	O
one	O
or	O
more	O
microprocessors	B-Architecture
may	O
be	O
installed	O
.	O
</s>
<s>
In	O
the	O
case	B-General_Concept
of	O
CPUs	B-Device
in	O
ball	B-Algorithm
grid	I-Algorithm
array	I-Algorithm
packages	O
,	O
such	O
as	O
the	O
VIA	B-Device
Nano	I-Device
and	O
the	O
Goldmont	B-Device
Plus	I-Device
,	O
the	O
CPU	B-Device
is	O
directly	O
soldered	O
to	O
the	O
motherboard	B-Device
.	O
</s>
<s>
Memory	B-General_Concept
slots	O
into	O
which	O
the	O
system	O
's	O
main	O
memory	B-General_Concept
is	O
to	O
be	O
installed	O
,	O
typically	O
in	O
the	O
form	O
of	O
DIMM	B-General_Concept
modules	O
containing	O
DRAM	O
chips	O
can	O
be	O
DDR3	O
,	O
DDR4	O
,	O
DDR5	O
,	O
or	O
onboard	O
LPDDRx	O
.	O
</s>
<s>
Power	O
connectors	O
,	O
which	O
receive	O
electrical	O
power	O
from	O
the	O
computer	O
power	O
supply	O
and	O
distribute	O
it	O
to	O
the	O
CPU	B-Device
,	O
chipset	B-Device
,	O
main	O
memory	B-General_Concept
,	O
and	O
expansion	B-Device
cards	I-Device
.	O
</s>
<s>
,	O
some	O
graphics	B-Device
cards	I-Device
(	O
e.g.	O
</s>
<s>
Connectors	O
for	O
hard	B-Device
disk	I-Device
drives	I-Device
,	O
optical	O
disc	O
drives	O
,	O
or	O
solid-state	B-Device
drives	I-Device
,	O
typically	O
SATA	O
and	O
NVMe	B-Application
now	O
.	O
</s>
<s>
Additionally	O
,	O
nearly	O
all	O
motherboards	B-Device
include	O
logic	O
and	O
connectors	O
to	O
support	O
commonly	O
used	O
input	O
devices	O
,	O
such	O
as	O
USB	B-Protocol
for	O
mouse	B-Device
devices	I-Device
and	O
keyboards	B-Device
.	O
</s>
<s>
Early	O
personal	B-Device
computers	I-Device
such	O
as	O
the	O
Apple	B-Device
II	I-Device
or	O
IBM	B-Device
PC	I-Device
included	O
only	O
this	O
minimal	O
peripheral	O
support	O
on	O
the	O
motherboard	B-Device
.	O
</s>
<s>
Occasionally	O
video	B-Device
interface	B-Application
hardware	B-Architecture
was	O
also	O
integrated	O
into	O
the	O
motherboard	B-Device
;	O
for	O
example	O
,	O
on	O
the	O
Apple	B-Device
II	I-Device
and	O
rarely	O
on	O
IBM-compatible	O
computers	O
such	O
as	O
the	O
IBM	B-Device
PC	I-Device
Jr.	I-Device
Additional	O
peripherals	B-Device
such	O
as	O
disk	B-General_Concept
controllers	I-General_Concept
and	O
serial	B-Protocol
ports	I-Protocol
were	O
provided	O
as	O
expansion	B-Device
cards	I-Device
.	O
</s>
<s>
Given	O
the	O
high	O
thermal	B-General_Concept
design	I-General_Concept
power	I-General_Concept
of	O
high-speed	O
computer	O
CPUs	B-Device
and	O
components	O
,	O
modern	O
motherboards	B-Device
nearly	O
always	O
include	O
heat	O
sinks	O
and	O
mounting	O
points	O
for	O
fans	O
to	O
dissipate	O
excess	O
heat	O
.	O
</s>
<s>
Motherboards	B-Device
are	O
produced	O
in	O
a	O
variety	O
of	O
sizes	O
and	O
shapes	O
called	O
form	O
factors	O
,	O
some	O
of	O
which	O
are	O
specific	O
to	O
individual	O
computer	O
manufacturers	O
.	O
</s>
<s>
However	O
,	O
the	O
motherboards	B-Device
used	O
in	O
IBM-compatible	O
systems	O
are	O
designed	O
to	O
fit	O
various	O
case	B-General_Concept
sizes	O
.	O
</s>
<s>
,	O
most	O
desktop	B-Device
computer	I-Device
motherboards	B-Device
use	O
the	O
ATX	B-Language
standard	O
form	O
factor	O
—	O
even	O
those	O
found	O
in	O
Macintosh	B-Device
and	O
Sun	O
computers	O
,	O
which	O
have	O
not	O
been	O
built	O
from	O
commodity	O
components	O
.	O
</s>
<s>
A	O
case	B-General_Concept
's	O
motherboard	B-Device
and	O
power	O
supply	O
unit	O
(	O
PSU	O
)	O
form	O
factor	O
must	O
all	O
match	O
,	O
though	O
some	O
smaller	O
form	O
factor	O
motherboards	B-Device
of	O
the	O
same	O
family	O
will	O
fit	O
larger	O
cases	O
.	O
</s>
<s>
For	O
example	O
,	O
an	O
ATX	B-Language
case	B-General_Concept
will	O
usually	O
accommodate	O
a	O
microATX	B-Device
motherboard	B-Device
.	O
</s>
<s>
Laptop	O
computers	O
generally	O
use	O
highly	O
integrated	O
,	O
miniaturized	O
,	O
and	O
customized	O
motherboards	B-Device
.	O
</s>
<s>
Often	O
the	O
failure	O
of	O
one	O
laptop	O
component	O
requires	O
the	O
replacement	O
of	O
the	O
entire	O
motherboard	B-Device
,	O
which	O
is	O
usually	O
more	O
expensive	O
than	O
a	O
desktop	O
motherboard	B-Device
.	O
</s>
<s>
A	O
CPU	B-General_Concept
socket	I-General_Concept
(	O
central	B-General_Concept
processing	I-General_Concept
unit	I-General_Concept
)	O
or	O
slot	O
is	O
an	O
electrical	O
component	O
that	O
attaches	O
to	O
a	O
printed	O
circuit	O
board	O
(	O
PCB	O
)	O
and	O
is	O
designed	O
to	O
house	O
a	O
CPU	B-Device
(	O
also	O
called	O
a	O
microprocessor	B-Architecture
)	O
.	O
</s>
<s>
A	O
CPU	B-General_Concept
socket	I-General_Concept
provides	O
many	O
functions	O
,	O
including	O
a	O
physical	O
structure	O
to	O
support	O
the	O
CPU	B-Device
,	O
support	O
for	O
a	O
heat	O
sink	O
,	O
facilitating	O
replacement	O
(	O
as	O
well	O
as	O
reducing	O
cost	O
)	O
,	O
and	O
most	O
importantly	O
,	O
forming	O
an	O
electrical	O
interface	B-Application
both	O
with	O
the	O
CPU	B-Device
and	O
the	O
PCB	O
.	O
</s>
<s>
CPU	B-General_Concept
sockets	I-General_Concept
on	O
the	O
motherboard	B-Device
can	O
most	O
often	O
be	O
found	O
in	O
most	O
desktop	O
and	O
server	B-Application
computers	I-Application
(	O
laptops	O
typically	O
use	O
surface	O
mount	O
CPUs	B-Device
)	O
,	O
particularly	O
those	O
based	O
on	O
the	O
Intel	B-Operating_System
x86	I-Operating_System
architecture	O
.	O
</s>
<s>
A	O
CPU	B-General_Concept
socket	I-General_Concept
type	O
and	O
motherboard	B-Device
chipset	B-Device
must	O
support	O
the	O
CPU	B-Device
series	O
and	O
speed	O
.	O
</s>
<s>
With	O
the	O
steadily	O
declining	O
costs	O
and	O
size	O
of	O
integrated	O
circuits	O
,	O
it	O
is	O
now	O
possible	O
to	O
include	O
support	O
for	O
many	O
peripherals	B-Device
on	O
the	O
motherboard	B-Device
.	O
</s>
<s>
By	O
combining	O
many	O
functions	O
on	O
one	O
PCB	O
,	O
the	O
physical	O
size	O
and	O
total	O
cost	O
of	O
the	O
system	O
may	O
be	O
reduced	O
;	O
highly	O
integrated	O
motherboards	B-Device
are	O
thus	O
especially	O
popular	O
in	O
small	B-Device
form	I-Device
factor	I-Device
and	O
budget	O
computers	O
.	O
</s>
<s>
Temperature	O
,	O
voltage	O
,	O
and	O
fan-speed	O
sensors	O
that	O
allow	O
software	O
to	O
monitor	O
the	O
health	O
of	O
computer	B-Architecture
components	I-Architecture
.	O
</s>
<s>
A	O
typical	O
motherboard	B-Device
will	O
have	O
a	O
different	O
number	O
of	O
connections	O
depending	O
on	O
its	O
standard	O
and	O
form	O
factor	O
.	O
</s>
<s>
A	O
standard	O
,	O
modern	O
ATX	B-Language
motherboard	B-Device
will	O
typically	O
have	O
two	O
or	O
three	O
PCI-Express	O
x16	O
connection	O
for	O
a	O
graphics	B-Device
card	I-Device
,	O
one	O
or	O
two	O
legacy	O
PCI	B-Protocol
slots	I-Protocol
for	O
various	O
expansion	B-Device
cards	I-Device
,	O
and	O
one	O
or	O
two	O
PCI-E	O
x1	O
(	O
which	O
has	O
superseded	O
PCI	B-Protocol
)	O
.	O
</s>
<s>
A	O
standard	O
EATX	O
motherboard	B-Device
will	O
have	O
two	O
to	O
four	O
PCI-E	O
x16	O
connection	O
for	O
graphics	B-Device
cards	I-Device
,	O
and	O
a	O
varying	O
number	O
of	O
PCI	B-Protocol
and	O
PCI-E	O
x1	O
slots	O
.	O
</s>
<s>
It	O
can	O
sometimes	O
also	O
have	O
a	O
PCI-E	O
x4	O
slot	O
(	O
will	O
vary	O
between	O
brands	O
and	O
models	O
)	O
.	O
</s>
<s>
Some	O
motherboards	B-Device
have	O
two	O
or	O
more	O
PCI-E	O
x16	O
slots	O
,	O
to	O
allow	O
more	O
than	O
2	O
monitors	O
without	O
special	O
hardware	B-Architecture
,	O
or	O
use	O
a	O
special	O
graphics	O
technology	O
called	O
SLI	B-Device
(	O
for	O
Nvidia	O
)	O
and	O
Crossfire	O
(	O
for	O
AMD	O
)	O
.	O
</s>
<s>
These	O
allow	O
2	O
to	O
4	O
graphics	B-Device
cards	I-Device
to	O
be	O
linked	O
together	O
,	O
to	O
allow	O
better	O
performance	O
in	O
intensive	O
graphical	O
computing	O
tasks	O
,	O
such	O
as	O
gaming	O
,	O
video	B-Device
editing	O
,	O
etc	O
.	O
</s>
<s>
In	O
newer	O
motherboards	B-Device
,	O
the	O
M.2	B-Protocol
slots	I-Protocol
are	O
for	O
SSD	B-Device
and/or	O
wireless	B-General_Concept
network	I-General_Concept
interface	I-General_Concept
controller	I-General_Concept
.	O
</s>
<s>
Motherboards	B-Device
are	O
generally	O
air	O
cooled	O
with	O
heat	O
sinks	O
often	O
mounted	O
on	O
larger	O
chips	O
in	O
modern	O
motherboards	B-Device
.	O
</s>
<s>
Insufficient	O
or	O
improper	O
cooling	O
can	O
cause	O
damage	O
to	O
the	O
internal	O
components	O
of	O
the	O
computer	O
,	O
or	O
cause	O
it	O
to	O
crash	B-General_Concept
.	O
</s>
<s>
Passive	O
cooling	O
,	O
or	O
a	O
single	O
fan	B-Application
mounted	O
on	O
the	O
power	O
supply	O
,	O
was	O
sufficient	O
for	O
many	O
desktop	B-Device
computer	I-Device
CPU	B-Device
's	O
until	O
the	O
late	O
1990s	O
;	O
since	O
then	O
,	O
most	O
have	O
required	O
CPU	B-Application
fans	I-Application
mounted	O
on	O
heat	O
sinks	O
,	O
due	O
to	O
rising	O
clock	O
speeds	O
and	O
power	O
consumption	O
.	O
</s>
<s>
Most	O
motherboards	B-Device
have	O
connectors	O
for	O
additional	O
computer	B-Application
fans	I-Application
and	O
integrated	O
temperature	O
sensors	O
to	O
detect	O
motherboard	B-Device
and	O
CPU	B-Device
temperatures	O
and	O
controllable	O
fan	B-Application
connectors	O
which	O
the	O
BIOS	B-Operating_System
or	O
operating	B-General_Concept
system	I-General_Concept
can	O
use	O
to	O
regulate	O
fan	B-Application
speed	O
.	O
</s>
<s>
Some	O
small	B-Device
form	I-Device
factor	I-Device
computers	O
and	O
home	O
theater	O
PCs	B-Device
designed	O
for	O
quiet	O
and	O
energy-efficient	O
operation	O
boast	O
fan-less	O
designs	O
.	O
</s>
<s>
This	O
typically	O
requires	O
the	O
use	O
of	O
a	O
low-power	O
CPU	B-Device
,	O
as	O
well	O
as	O
a	O
careful	O
layout	O
of	O
the	O
motherboard	B-Device
and	O
other	O
components	O
to	O
allow	O
for	O
heat	O
sink	O
placement	O
.	O
</s>
<s>
A	O
2003	O
study	O
found	O
that	O
some	O
spurious	O
computer	B-General_Concept
crashes	I-General_Concept
and	O
general	O
reliability	O
issues	O
,	O
ranging	O
from	O
screen	O
image	O
distortions	O
to	O
I/O	B-General_Concept
read/write	O
errors	O
,	O
can	O
be	O
attributed	O
not	O
to	O
software	O
or	O
peripheral	O
hardware	B-Architecture
but	O
to	O
aging	O
capacitors	O
on	O
PC	B-Device
motherboards	I-Device
.	O
</s>
<s>
Modern	O
motherboards	B-Device
use	O
electrolytic	O
capacitors	O
to	O
filter	O
the	O
DC	O
power	O
distributed	O
around	O
the	O
board	O
.	O
</s>
<s>
This	O
can	O
lead	O
to	O
loss	O
of	O
capacitance	O
and	O
subsequent	O
motherboard	B-Device
malfunctions	O
due	O
to	O
voltage	O
instabilities	O
.	O
</s>
<s>
Inadequate	O
case	B-General_Concept
cooling	O
and	O
elevated	O
temperatures	O
around	O
the	O
CPU	B-General_Concept
socket	I-General_Concept
exacerbate	O
this	O
problem	O
.	O
</s>
<s>
With	O
top	O
blowers	O
,	O
the	O
motherboard	B-Device
components	O
can	O
be	O
kept	O
under	O
,	O
effectively	O
doubling	O
the	O
motherboard	B-Device
lifetime	O
.	O
</s>
<s>
Mid-range	O
and	O
high-end	O
motherboards	B-Device
,	O
on	O
the	O
other	O
hand	O
,	O
use	O
solid	O
capacitors	O
exclusively	O
.	O
</s>
<s>
In	O
Desktop	B-Device
PCs	I-Device
and	O
notebook	O
computers	O
,	O
the	O
motherboard	B-Device
cooling	O
and	O
monitoring	O
solutions	O
are	O
usually	O
based	O
on	O
Super	B-Device
I/O	I-Device
or	O
Embedded	B-Architecture
Controller	I-Architecture
.	O
</s>
<s>
Motherboards	B-Device
contain	O
a	O
ROM	B-Device
(	O
and	O
later	O
EPROM	B-General_Concept
,	O
EEPROM	B-General_Concept
,	O
NOR	O
flash	O
)	O
to	O
initialize	O
hardware	B-Architecture
devices	O
and	O
load	O
an	O
operating	B-General_Concept
system	I-General_Concept
from	O
a	O
peripheral	B-Device
device	I-Device
.	O
</s>
<s>
Microcomputers	O
such	O
as	O
the	O
Apple	B-Device
II	I-Device
and	O
IBM	B-Device
PC	I-Device
used	O
ROM	B-Device
chips	I-Device
mounted	O
in	O
sockets	O
on	O
the	O
motherboard	B-Device
.	O
</s>
<s>
At	O
power-up	O
,	O
the	O
central	O
processor	O
unit	O
would	O
load	O
its	O
program	B-General_Concept
counter	I-General_Concept
with	O
the	O
address	O
of	O
the	O
Boot	B-Operating_System
ROM	B-Device
and	O
start	O
executing	O
instructions	O
from	O
the	O
Boot	B-Operating_System
ROM	B-Device
.	O
</s>
<s>
These	O
instructions	O
initialized	O
and	O
tested	O
the	O
system	O
hardware	B-Architecture
,	O
displayed	O
system	O
information	O
on	O
the	O
screen	O
,	O
performed	O
RAM	B-Architecture
checks	O
,	O
and	O
then	O
loaded	O
an	O
operating	B-General_Concept
system	I-General_Concept
from	O
a	O
peripheral	B-Device
device	I-Device
.	O
</s>
<s>
If	O
none	O
was	O
available	O
,	O
then	O
the	O
computer	O
would	O
perform	O
tasks	O
from	O
other	O
ROM	B-Device
stores	O
or	O
display	O
an	O
error	O
message	O
,	O
depending	O
on	O
the	O
model	O
and	O
design	O
of	O
the	O
computer	O
.	O
</s>
<s>
For	O
example	O
,	O
both	O
the	O
Apple	B-Device
II	I-Device
and	O
the	O
original	O
IBM	B-Device
PC	I-Device
had	O
Cassette	O
BASIC	O
(	O
ROM	B-Device
BASIC	O
)	O
and	O
would	O
start	O
that	O
if	O
no	O
operating	B-General_Concept
system	I-General_Concept
could	O
be	O
loaded	O
from	O
the	O
floppy	B-Device
disk	I-Device
or	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
Most	O
modern	O
motherboard	B-Device
designs	O
use	O
a	O
BIOS	B-Operating_System
,	O
stored	O
in	O
an	O
EEPROM	B-General_Concept
or	O
NOR	O
flash	B-Device
chip	I-Device
soldered	O
to	O
or	O
socketed	O
on	O
the	O
motherboard	B-Device
,	O
to	O
boot	B-Operating_System
an	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
When	O
the	O
computer	O
is	O
powered	O
on	O
,	O
the	O
BIOS	B-Operating_System
firmware	B-Application
tests	O
and	O
configures	O
memory	B-General_Concept
,	O
circuitry	O
,	O
and	O
peripherals	B-Device
.	O
</s>
<s>
This	O
Power-On	B-Device
Self	I-Device
Test	I-Device
(	O
POST	O
)	O
may	O
include	O
testing	O
some	O
of	O
the	O
following	O
things	O
:	O
</s>
<s>
Many	O
motherboards	B-Device
now	O
use	O
a	O
successor	O
to	O
BIOS	B-Operating_System
called	O
UEFI	B-Architecture
.	O
</s>
<s>
It	O
became	O
popular	O
after	O
Microsoft	O
began	O
requiring	O
it	O
for	O
a	O
system	O
to	O
be	O
certified	O
to	O
run	O
Windows	B-Application
8	I-Application
.	O
</s>
