<s>
In	O
computing	O
,	O
overclocking	B-Application
is	O
the	O
practice	O
of	O
increasing	O
the	O
clock	O
rate	O
of	O
a	O
computer	O
to	O
exceed	O
that	O
certified	O
by	O
the	O
manufacturer	O
.	O
</s>
<s>
Many	O
device	O
warranties	O
state	O
that	O
overclocking	B-Application
or	O
over-specification	O
voids	O
any	O
warranty	O
,	O
but	O
some	O
manufacturers	O
allow	O
overclocking	B-Application
as	O
long	O
as	O
it	O
is	O
done	O
(	O
relatively	O
)	O
safely	O
.	O
</s>
<s>
The	O
purpose	O
of	O
overclocking	B-Application
is	O
to	O
increase	O
the	O
operating	O
speed	O
of	O
a	O
given	O
component	O
.	O
</s>
<s>
Normally	O
,	O
on	O
modern	O
systems	O
,	O
the	O
target	O
of	O
overclocking	B-Application
is	O
increasing	O
the	O
performance	O
of	O
a	O
major	O
chip	O
or	O
subsystem	O
,	O
such	O
as	O
the	O
main	O
processor	O
or	O
graphics	B-Device
controller	I-Device
,	O
but	O
other	O
components	O
,	O
such	O
as	O
system	O
memory	O
(	O
RAM	B-Architecture
)	O
or	O
system	B-General_Concept
buses	I-General_Concept
(	O
generally	O
on	O
the	O
motherboard	B-Device
)	O
,	O
are	O
commonly	O
involved	O
.	O
</s>
<s>
Overclocking	B-Application
techniques	O
in	O
general	O
aim	O
to	O
trade	O
this	O
safety	O
margin	O
by	O
setting	O
the	O
device	O
to	O
run	O
in	O
the	O
higher	O
end	O
of	O
the	O
margin	O
,	O
with	O
the	O
understanding	O
that	O
temperature	O
and	O
voltage	O
must	O
be	O
more	O
strictly	O
monitored	O
and	O
controlled	O
by	O
the	O
user	O
.	O
</s>
<s>
While	O
most	O
modern	O
devices	O
are	O
fairly	O
tolerant	O
of	O
overclocking	B-Application
,	O
all	O
devices	O
have	O
finite	O
limits	O
.	O
</s>
<s>
While	O
in	O
a	O
PC	O
context	O
the	O
usual	O
result	O
is	O
a	O
system	O
crash	O
,	O
more	O
subtle	O
errors	O
can	O
go	O
undetected	O
,	O
which	O
over	O
a	O
long	O
enough	O
time	O
can	O
give	O
unpleasant	O
surprises	O
such	O
as	O
data	O
corruption	O
(	O
incorrectly	O
calculated	O
results	O
,	O
or	O
worse	O
writing	O
to	O
storage	O
incorrectly	O
)	O
or	O
the	O
system	O
failing	O
only	O
during	O
certain	O
specific	O
tasks	O
(	O
general	O
usage	O
such	O
as	O
internet	O
browsing	O
and	O
word	B-General_Concept
processing	I-General_Concept
appear	O
fine	O
,	O
but	O
any	O
application	O
wanting	O
advanced	O
graphics	O
crashes	O
the	O
system	O
)	O
.	O
</s>
<s>
The	O
speed	O
gained	O
by	O
overclocking	B-Application
depends	O
largely	O
upon	O
the	O
applications	O
and	O
workloads	O
being	O
run	O
on	O
the	O
system	O
,	O
and	O
what	O
components	O
are	O
being	O
overclocked	O
by	O
the	O
user	O
;	O
benchmarks	O
for	O
different	O
purposes	O
are	O
published	O
.	O
</s>
<s>
Conversely	O
,	O
the	O
primary	O
goal	O
of	O
underclocking	B-Device
is	O
to	O
reduce	O
power	O
consumption	O
and	O
the	O
resultant	O
heat	O
generation	O
of	O
a	O
device	O
,	O
with	O
the	O
trade-offs	O
being	O
lower	O
clock	O
speeds	O
and	O
reductions	O
in	O
performance	O
.	O
</s>
<s>
Some	O
manufacturers	O
underclock	B-Device
components	O
of	O
battery-powered	O
equipment	O
to	O
improve	O
battery	O
life	O
,	O
or	O
implement	O
systems	O
that	O
detect	O
when	O
a	O
device	O
is	O
operating	O
under	O
battery	O
power	O
and	O
reduce	O
clock	O
frequency	O
.	O
</s>
<s>
Underclocking	B-Device
and	O
undervolting	O
would	O
be	O
attempted	O
on	O
a	O
desktop	O
system	O
to	O
have	O
it	O
operate	O
silently	O
(	O
such	O
as	O
for	O
a	O
home	O
entertainment	O
center	O
)	O
while	O
potentially	O
offering	O
higher	O
performance	O
than	O
currently	O
offered	O
by	O
low-voltage	O
processor	O
offerings	O
.	O
</s>
<s>
However	O
again	O
like	O
overclocking	B-Application
there	O
is	O
no	O
guarantee	O
of	O
success	O
,	O
and	O
the	O
builder	O
's	O
time	O
researching	O
given	O
system/processor	O
combinations	O
and	O
especially	O
the	O
time	O
and	O
tedium	O
of	O
performing	O
many	O
iterations	O
of	O
stability	O
testing	O
need	O
to	O
be	O
considered	O
.	O
</s>
<s>
The	O
usefulness	O
of	O
underclocking	B-Device
(	O
again	O
like	O
overclocking	B-Application
)	O
is	O
determined	O
by	O
what	O
processor	O
offerings	O
,	O
prices	O
,	O
and	O
availability	O
are	O
at	O
the	O
specific	O
time	O
of	O
the	O
build	O
.	O
</s>
<s>
Underclocking	B-Device
is	O
also	O
sometimes	O
used	O
when	O
troubleshooting	O
.	O
</s>
<s>
Overclocking	B-Application
has	O
become	O
more	O
accessible	O
with	O
motherboard	B-Device
makers	O
offering	O
overclocking	B-Application
as	O
a	O
marketing	O
feature	O
on	O
their	O
mainstream	O
product	O
lines	O
.	O
</s>
<s>
However	O
,	O
the	O
practice	O
is	O
embraced	O
more	O
by	O
enthusiasts	O
than	O
professional	O
users	O
,	O
as	O
overclocking	B-Application
carries	O
a	O
risk	O
of	O
reduced	O
reliability	O
,	O
accuracy	O
and	O
damage	O
to	O
data	O
and	O
equipment	O
.	O
</s>
<s>
While	O
overclocking	B-Application
can	O
still	O
be	O
an	O
option	O
for	O
increasing	O
personal	O
computing	O
capacity	O
,	O
and	O
thus	O
workflow	O
productivity	O
for	O
professional	O
users	O
,	O
the	O
importance	O
of	O
stability	O
testing	O
components	O
thoroughly	O
before	O
employing	O
them	O
into	O
a	O
production	O
environment	O
cannot	O
be	O
overstated	O
.	O
</s>
<s>
Overclocking	B-Application
offers	O
several	O
draws	O
for	O
overclocking	B-Application
enthusiasts	O
.	O
</s>
<s>
Overclocking	B-Application
allows	O
testing	O
of	O
components	O
at	O
speeds	O
not	O
currently	O
offered	O
by	O
the	O
manufacturer	O
,	O
or	O
at	O
speeds	O
only	O
officially	O
offered	O
on	O
specialized	O
,	O
higher-priced	O
versions	O
of	O
the	O
product	O
.	O
</s>
<s>
If	O
the	O
high-end	O
part	O
only	O
differs	O
by	O
an	O
increased	O
clock	O
speed	O
,	O
an	O
enthusiast	O
can	O
attempt	O
to	O
overclock	B-Application
a	O
mainstream	O
part	O
to	O
simulate	O
the	O
high-end	O
offering	O
.	O
</s>
<s>
Others	O
will	O
purchase	O
a	O
low-cost	O
model	O
of	O
a	O
component	O
in	O
a	O
given	O
product	O
line	O
,	O
and	O
attempt	O
to	O
overclock	B-Application
that	O
part	O
to	O
match	O
a	O
more	O
expensive	O
model	O
's	O
stock	O
performance	O
.	O
</s>
<s>
Another	O
approach	O
is	O
overclocking	B-Application
older	O
components	O
to	O
attempt	O
to	O
keep	O
pace	O
with	O
increasing	O
system	O
requirements	O
and	O
extend	O
the	O
useful	O
service	O
life	O
of	O
the	O
older	O
part	O
or	O
at	O
least	O
delay	O
a	O
purchase	O
of	O
new	O
hardware	O
solely	O
for	O
performance	O
reasons	O
.	O
</s>
<s>
Another	O
rationale	O
for	O
overclocking	B-Application
older	O
equipment	O
is	O
even	O
if	O
overclocking	B-Application
stresses	O
equipment	O
to	O
the	O
point	O
of	O
failure	O
earlier	O
,	O
little	O
is	O
lost	O
as	O
it	O
is	O
already	O
depreciated	O
,	O
and	O
would	O
have	O
needed	O
to	O
be	O
replaced	O
in	O
any	O
case	O
.	O
</s>
<s>
Most	O
efforts	O
for	O
computer	O
components	O
however	O
focus	O
on	O
specific	O
components	O
,	O
such	O
as	O
,	O
processors	B-General_Concept
(	O
a.k.a.	O
</s>
<s>
CPU	B-General_Concept
)	O
,	O
video	B-Device
cards	I-Device
,	O
motherboard	B-Device
chipsets	B-Device
,	O
and	O
RAM	B-Architecture
.	O
</s>
<s>
Most	O
modern	O
processors	B-General_Concept
derive	O
their	O
effective	O
operating	O
speeds	O
by	O
multiplying	O
a	O
base	O
clock	O
(	O
processor	O
bus	O
speed	O
)	O
by	O
an	O
internal	O
multiplier	O
within	O
the	O
processor	O
(	O
the	O
CPU	B-General_Concept
multiplier	O
)	O
to	O
attain	O
their	O
final	O
speed	O
.	O
</s>
<s>
Computer	O
processors	B-General_Concept
generally	O
are	O
overclocked	O
by	O
manipulating	O
the	O
CPU	B-General_Concept
multiplier	O
if	O
that	O
option	O
is	O
available	O
,	O
but	O
the	O
processor	O
and	O
other	O
components	O
can	O
also	O
be	O
overclocked	O
by	O
increasing	O
the	O
base	O
speed	O
of	O
the	O
bus	B-Architecture
clock	I-Architecture
.	O
</s>
<s>
Some	O
systems	O
allow	O
additional	O
tuning	O
of	O
other	O
clocks	O
(	O
such	O
as	O
a	O
system	O
clock	O
)	O
that	O
influence	O
the	O
bus	B-Architecture
clock	I-Architecture
speed	O
that	O
,	O
again	O
is	O
multiplied	O
by	O
the	O
processor	O
to	O
allow	O
for	O
finer	O
adjustments	O
of	O
the	O
final	O
processor	O
speed	O
.	O
</s>
<s>
Most	O
OEM	O
systems	O
do	O
not	O
expose	O
to	O
the	O
user	O
the	O
adjustments	O
needed	O
to	O
change	O
processor	O
clock	O
speed	O
or	O
voltage	O
in	O
the	O
BIOS	B-Operating_System
of	O
the	O
OEM	O
's	O
motherboard	B-Device
,	O
which	O
precludes	O
overclocking	B-Application
(	O
for	O
warranty	O
and	O
support	O
reasons	O
)	O
.	O
</s>
<s>
The	O
same	O
processor	O
installed	O
on	O
a	O
different	O
motherboard	B-Device
offering	O
adjustments	O
will	O
allow	O
the	O
user	O
to	O
change	O
them	O
.	O
</s>
<s>
The	O
maximum	O
speed	O
is	O
determined	O
by	O
overclocking	B-Application
to	O
the	O
point	O
of	O
first	O
instability	O
,	O
then	O
accepting	O
the	O
last	O
stable	O
slower	O
setting	O
.	O
</s>
<s>
Components	O
are	O
only	O
guaranteed	O
to	O
operate	O
correctly	O
up	O
to	O
their	O
rated	O
values	O
;	O
beyond	O
that	O
different	O
samples	O
may	O
have	O
different	O
overclocking	B-Application
potential	O
.	O
</s>
<s>
The	O
end-point	O
of	O
a	O
given	O
overclock	B-Application
is	O
determined	O
by	O
parameters	O
such	O
as	O
available	O
CPU	B-General_Concept
multipliers	O
,	O
bus	O
dividers	O
,	O
voltages	O
;	O
the	O
user	O
's	O
ability	O
to	O
manage	O
thermal	O
loads	O
,	O
cooling	O
techniques	O
;	O
and	O
several	O
other	O
factors	O
of	O
the	O
individual	O
devices	O
themselves	O
such	O
as	O
semiconductor	O
clock	O
and	O
thermal	O
tolerances	O
,	O
interaction	O
with	O
other	O
components	O
and	O
the	O
rest	O
of	O
the	O
system	O
.	O
</s>
<s>
There	O
are	O
several	O
things	O
to	O
be	O
considered	O
when	O
overclocking	B-Application
.	O
</s>
<s>
In	O
a	O
professional	O
production	O
environment	O
,	O
overclocking	B-Application
is	O
only	O
likely	O
to	O
be	O
used	O
where	O
the	O
increase	O
in	O
speed	O
justifies	O
the	O
cost	O
of	O
the	O
expert	O
support	O
required	O
,	O
the	O
possibly	O
reduced	O
reliability	O
,	O
the	O
consequent	O
effect	O
on	O
maintenance	O
contracts	O
and	O
warranties	O
,	O
and	O
the	O
higher	O
power	O
consumption	O
.	O
</s>
<s>
The	O
relationship	O
between	O
clock	O
frequencies	O
and	O
thermal	B-General_Concept
design	I-General_Concept
power	I-General_Concept
(	O
TDP	O
)	O
are	O
linear	O
.	O
</s>
<s>
To	O
overcome	O
this	O
issue	O
,	O
overclockers	B-Application
raise	O
the	O
chip	O
voltage	O
to	O
increase	O
the	O
overclocking	B-Application
potential	O
.	O
</s>
<s>
In	O
addition	O
,	O
some	O
digital	O
circuits	O
slow	O
down	O
at	O
high	O
temperatures	O
due	O
to	O
changes	O
in	O
MOSFET	B-Architecture
device	O
characteristics	O
.	O
</s>
<s>
Conversely	O
,	O
the	O
overclocker	B-Application
may	O
decide	O
to	O
decrease	O
the	O
chip	O
voltage	O
while	O
overclocking	B-Application
(	O
a	O
process	O
known	O
as	O
undervolting	O
)	O
,	O
to	O
reduce	O
heat	O
emissions	O
while	O
performance	O
remains	O
optimal	O
.	O
</s>
<s>
Thermoelectric	O
cooling	O
devices	O
which	O
actually	O
refrigerate	O
using	O
the	O
Peltier	O
effect	O
can	O
help	O
with	O
high	O
thermal	B-General_Concept
design	I-General_Concept
power	I-General_Concept
(	O
TDP	O
)	O
processors	B-General_Concept
made	O
by	O
Intel	O
and	O
AMD	O
in	O
the	O
early	O
twenty-first	O
century	O
.	O
</s>
<s>
In	O
June	O
2006	O
,	O
IBM	O
and	O
Georgia	O
Institute	O
of	O
Technology	O
jointly	O
announced	O
a	O
new	O
record	O
in	O
silicon-based	O
chip	O
clock	O
rate	O
(	O
the	O
rate	O
a	O
transistor	O
can	O
be	O
switched	O
at	O
,	O
not	O
the	O
CPU	B-General_Concept
clock	O
rate	O
)	O
above	O
500GHz	O
,	O
which	O
was	O
done	O
by	O
cooling	O
the	O
chip	O
to	O
using	O
liquid	O
helium	O
.	O
</s>
<s>
Set	O
in	O
November	O
2012	O
,	O
the	O
CPU	B-General_Concept
Frequency	O
World	O
Record	O
is	O
8.794GHz	O
as	O
of	O
January	O
2022	O
.	O
</s>
<s>
Submersion	O
cooling	O
,	O
used	O
by	O
the	O
Cray-2	B-Device
supercomputer	B-Architecture
,	O
involves	O
sinking	O
a	O
part	O
of	O
computer	O
system	O
directly	O
into	O
a	O
chilled	O
liquid	O
that	O
is	O
thermally	O
conductive	O
but	O
has	O
low	O
electrical	O
conductivity	O
.	O
</s>
<s>
Amateur	O
overclocking	B-Application
enthusiasts	O
have	O
used	O
a	O
mixture	O
of	O
dry	O
ice	O
and	O
a	O
solvent	O
with	O
a	O
low	O
freezing	O
point	O
,	O
such	O
as	O
acetone	O
or	O
isopropyl	O
alcohol	O
.	O
</s>
<s>
However	O
,	O
this	O
practice	O
is	O
discouraged	O
due	O
to	O
its	O
safety	O
risks	O
;	O
the	O
solvents	O
are	O
flammable	O
and	O
volatile	O
,	O
and	O
dry	O
ice	O
can	O
cause	O
frostbite	B-Operating_System
(	O
through	O
contact	O
with	O
exposed	O
skin	O
)	O
and	O
suffocation	O
(	O
due	O
to	O
the	O
large	O
volume	O
of	O
carbon	O
dioxide	O
generated	O
when	O
it	O
sublimes	O
)	O
.	O
</s>
<s>
Another	O
risk	O
is	O
silent	B-General_Concept
data	I-General_Concept
corruption	I-General_Concept
by	O
undetected	O
errors	O
.	O
</s>
<s>
Such	O
failures	O
might	O
never	O
be	O
correctly	O
diagnosed	O
and	O
may	O
instead	O
be	O
incorrectly	O
attributed	O
to	O
software	O
bugs	O
in	O
applications	O
,	O
device	B-Application
drivers	I-Application
,	O
or	O
the	O
operating	O
system	O
.	O
</s>
<s>
A	O
large-scale	O
2011	O
field	O
study	O
of	O
hardware	O
faults	O
causing	O
a	O
system	O
crash	O
for	O
consumer	O
PCs	O
and	O
laptops	O
showed	O
a	O
four	O
to	O
20	O
times	O
increase	O
(	O
depending	O
on	O
CPU	B-General_Concept
manufacturer	O
)	O
in	O
system	O
crashes	O
due	O
to	O
CPU	B-General_Concept
failure	O
for	O
overclocked	O
computers	O
over	O
an	O
eight-month	O
period	O
.	O
</s>
<s>
In	O
general	O
,	O
overclockers	B-Application
claim	O
that	O
testing	O
can	O
ensure	O
that	O
an	O
overclocked	O
system	O
is	O
stable	O
and	O
functioning	O
correctly	O
.	O
</s>
<s>
For	O
example	O
,	O
an	O
arithmetic	O
operation	O
may	O
produce	O
the	O
correct	O
result	O
but	O
incorrect	O
flags	B-General_Concept
;	O
if	O
the	O
flags	B-General_Concept
are	O
not	O
checked	O
,	O
the	O
error	O
will	O
go	O
undetected	O
.	O
</s>
<s>
To	O
further	O
complicate	O
matters	O
,	O
in	O
process	O
technologies	O
such	O
as	O
silicon	B-Algorithm
on	I-Algorithm
insulator	I-Algorithm
(	O
SOI	O
)	O
,	O
devices	O
display	O
hysteresisa	O
circuit	O
's	O
performance	O
is	O
affected	O
by	O
the	O
events	O
of	O
the	O
past	O
,	O
so	O
without	O
carefully	O
targeted	O
tests	O
it	O
is	O
possible	O
for	O
a	O
particular	O
sequence	O
of	O
state	O
changes	O
to	O
work	O
at	O
overclocked	O
rates	O
in	O
one	O
situation	O
but	O
not	O
another	O
even	O
if	O
the	O
voltage	O
and	O
temperature	O
are	O
the	O
same	O
.	O
</s>
<s>
In	O
overclocking	B-Application
circles	O
,	O
"	O
stress	O
tests	O
"	O
or	O
"	O
torture	O
tests	O
"	O
are	O
used	O
to	O
check	O
for	O
correct	O
operation	O
of	O
a	O
component	O
.	O
</s>
<s>
a	O
graphically	O
intensive	O
application	O
for	O
testing	O
video	B-Device
cards	I-Device
,	O
or	O
different	O
math-intensive	O
applications	O
for	O
testing	O
general	O
CPUs	O
)	O
.	O
</s>
<s>
Popular	O
stress	O
tests	O
include	O
Prime95	B-Device
,	O
Everest	O
,	O
Superpi	O
,	O
OCCT	O
,	O
AIDA64	O
,	O
Linpack	B-Application
(	O
via	O
the	O
LinX	O
and	O
IntelBurnTest	O
GUIs	B-Application
)	O
,	O
SiSoftware	O
Sandra	O
,	O
BOINC	B-Operating_System
,	O
Intel	O
Thermal	O
Analysis	O
Tool	O
and	O
Memtest86	B-Application
.	O
</s>
<s>
Pentium	O
architect	O
Bob	O
Colwell	O
calls	O
overclocking	B-Application
an	O
"	O
uncontrolled	O
experiment	O
in	O
better-than-worst-case	O
system	O
operation	O
"	O
.	O
</s>
<s>
As	O
discussed	O
above	O
,	O
stability	O
and	O
functional	O
correctness	O
may	O
be	O
compromised	O
when	O
overclocking	B-Application
,	O
and	O
meaningful	O
benchmark	O
results	O
depend	O
on	O
the	O
correct	O
execution	O
of	O
the	O
benchmark	O
.	O
</s>
<s>
an	O
overclocker	B-Application
may	O
report	O
a	O
score	O
,	O
noting	O
that	O
the	O
benchmark	O
only	O
runs	O
to	O
completion	O
1	O
in	O
5	O
times	O
,	O
or	O
that	O
signs	O
of	O
incorrect	O
execution	O
such	O
as	O
display	O
corruption	O
are	O
visible	O
while	O
running	O
the	O
benchmark	O
)	O
.	O
</s>
<s>
A	O
widely	O
used	O
test	O
of	O
stability	O
is	O
Prime95	B-Device
,	O
which	O
has	O
built-in	O
error	O
checking	O
that	O
fails	O
if	O
the	O
computer	O
is	O
unstable	O
.	O
</s>
<s>
Using	O
only	O
the	O
benchmark	O
scores	O
,	O
it	O
may	O
be	O
difficult	O
to	O
judge	O
the	O
difference	O
overclocking	B-Application
makes	O
to	O
the	O
overall	O
performance	O
of	O
a	O
computer	O
.	O
</s>
<s>
For	O
example	O
,	O
some	O
benchmarks	O
test	O
only	O
one	O
aspect	O
of	O
the	O
system	O
,	O
such	O
as	O
memory	B-General_Concept
bandwidth	I-General_Concept
,	O
without	O
taking	O
into	O
consideration	O
how	O
higher	O
clock	O
rates	O
in	O
this	O
aspect	O
will	O
improve	O
the	O
system	O
performance	O
as	O
a	O
whole	O
.	O
</s>
<s>
Apart	O
from	O
demanding	O
applications	O
such	O
as	O
video	O
encoding	O
,	O
high-demand	O
databases	O
and	O
scientific	O
computing	O
,	O
memory	B-General_Concept
bandwidth	I-General_Concept
is	O
typically	O
not	O
a	O
bottleneck	O
,	O
so	O
a	O
great	O
increase	O
in	O
memory	B-General_Concept
bandwidth	I-General_Concept
may	O
be	O
unnoticeable	O
to	O
a	O
user	O
depending	O
on	O
the	O
applications	O
used	O
.	O
</s>
<s>
Overclocking	B-Application
is	O
sometimes	O
offered	O
as	O
a	O
legitimate	O
service	O
or	O
feature	O
for	O
consumers	O
,	O
in	O
which	O
a	O
manufacturer	O
or	O
retailer	O
tests	O
the	O
overclocking	B-Application
capability	O
of	O
processors	B-General_Concept
,	O
memory	O
,	O
video	B-Device
cards	I-Device
,	O
and	O
other	O
hardware	O
products	O
.	O
</s>
<s>
Several	O
video	B-Device
card	I-Device
manufactures	O
now	O
offer	O
factory-overclocked	O
versions	O
of	O
their	O
graphics	B-Architecture
accelerators	I-Architecture
,	O
complete	O
with	O
a	O
warranty	O
,	O
usually	O
at	O
a	O
price	O
intermediate	O
between	O
that	O
of	O
the	O
standard	O
product	O
and	O
a	O
non-overclocked	O
product	O
of	O
higher	O
performance	O
.	O
</s>
<s>
It	O
is	O
speculated	O
that	O
manufacturers	O
implement	O
overclocking	B-Application
prevention	O
mechanisms	O
such	O
as	O
CPU	B-General_Concept
multiplier	O
locking	O
to	O
prevent	O
users	O
from	O
buying	O
lower-priced	O
items	O
and	O
overclocking	B-Application
them	O
.	O
</s>
<s>
Many	O
motherboards	B-Device
are	O
sold	O
,	O
and	O
advertised	O
,	O
with	O
extensive	O
facilities	O
for	O
overclocking	B-Application
implemented	O
in	O
hardware	O
and	O
controlled	O
by	O
BIOS	B-Operating_System
settings	I-Operating_System
.	O
</s>
<s>
CPU	B-General_Concept
multiplier	O
locking	O
is	O
the	O
process	O
of	O
permanently	O
setting	O
a	O
CPU	B-General_Concept
's	O
clock	O
multiplier	O
.	O
</s>
<s>
AMD	O
CPUs	O
are	O
unlocked	O
in	O
early	O
editions	O
of	O
a	O
model	O
and	O
locked	O
in	O
later	O
editions	O
,	O
but	O
nearly	O
all	O
Intel	O
CPUs	O
are	O
locked	O
and	O
recent	O
models	O
are	O
very	O
resistant	O
to	O
unlocking	O
to	O
prevent	O
overclocking	B-Application
by	O
users	O
.	O
</s>
<s>
AMD	O
ships	O
unlocked	O
CPUs	O
with	O
their	O
Opteron	B-General_Concept
,	O
FX	O
,	O
All	O
Ryzen	O
desktop	O
chips	O
(	O
except	O
3D	O
variants	O
)	O
and	O
Black	O
Series	O
line-up	O
,	O
while	O
Intel	O
uses	O
the	O
monikers	O
of	O
"	O
Extreme	O
Edition	O
"	O
and	O
"	O
K-Series.	O
"	O
</s>
<s>
Users	O
usually	O
unlock	O
CPUs	O
to	O
allow	O
overclocking	B-Application
,	O
but	O
sometimes	O
to	O
allow	O
for	O
underclocking	B-Device
in	O
order	O
to	O
maintain	O
the	O
front	B-Architecture
side	I-Architecture
bus	I-Architecture
speed	O
(	O
on	O
older	O
CPUs	O
)	O
compatibility	O
with	O
certain	O
motherboards	B-Device
.	O
</s>
<s>
Unlocking	O
generally	O
invalidates	O
the	O
manufacturer	O
's	O
warranty	O
,	O
and	O
mistakes	O
can	O
cripple	O
or	O
destroy	O
a	O
CPU	B-General_Concept
.	O
</s>
<s>
Locking	O
a	O
chip	O
's	O
clock	O
multiplier	O
does	O
not	O
necessarily	O
prevent	O
users	O
from	O
overclocking	B-Application
,	O
as	O
the	O
speed	O
of	O
the	O
front-side	B-Architecture
bus	I-Architecture
or	O
PCI	O
multiplier	O
(	O
on	O
newer	O
CPUs	O
)	O
may	O
still	O
be	O
changed	O
to	O
provide	O
a	O
performance	O
increase	O
.	O
</s>
<s>
AMD	B-Architecture
Athlon	I-Architecture
and	O
Athlon	B-Architecture
XP	O
CPUs	O
are	O
generally	O
unlocked	O
by	O
connecting	O
bridges	O
(	O
jumper-like	O
points	O
)	O
on	O
the	O
top	O
of	O
the	O
CPU	B-General_Concept
with	O
conductive	O
paint	O
or	O
pencil	B-Application
lead	I-Application
.	O
</s>
<s>
Other	O
CPU	B-General_Concept
models	O
may	O
require	O
different	O
procedures	O
.	O
</s>
<s>
Increasing	O
front-side	B-Architecture
bus	I-Architecture
or	O
northbridge/PCI	O
clocks	O
can	O
overclock	B-Application
locked	O
CPUs	O
,	O
but	O
this	O
throws	O
many	O
system	O
frequencies	O
out	O
of	O
sync	O
,	O
since	O
the	O
RAM	B-Architecture
and	O
PCI	O
frequencies	O
are	O
modified	O
as	O
well	O
.	O
</s>
<s>
All	O
other	O
unlocked	O
processors	B-General_Concept
from	O
LGA1151	O
and	O
v2	O
(	O
including	O
7th	O
,	O
8th	O
,	O
and	O
9th	O
generation	O
)	O
and	O
BGA1440	O
allow	O
for	O
BCLK	O
overclocking	B-Application
(	O
as	O
long	O
as	O
the	O
OEM	O
allows	O
it	O
)	O
,	O
while	O
all	O
other	O
locked	O
processors	B-General_Concept
from	O
7th	O
,	O
8th	O
,	O
and	O
9th	O
gen	O
were	O
not	O
able	O
to	O
go	O
past	O
102.7	O
Mhz	O
.	O
</s>
<s>
System	O
optimization	O
:	O
Some	O
systems	O
have	O
"	O
bottlenecks	O
"	O
,	O
where	O
small	O
overclocking	B-Application
of	O
one	O
component	O
can	O
help	O
realize	O
the	O
full	O
potential	O
of	O
another	O
component	O
to	O
a	O
greater	O
percentage	O
than	O
when	O
just	O
the	O
limiting	O
hardware	O
itself	O
is	O
overclocked	O
.	O
</s>
<s>
For	O
instance	O
:	O
many	O
motherboards	B-Device
with	O
AMD	B-Architecture
Athlon	I-Architecture
64	O
processors	B-General_Concept
limit	O
the	O
clock	O
rate	O
of	O
four	O
units	O
of	O
RAM	B-Architecture
to	O
333	O
MHz	O
.	O
</s>
<s>
However	O
,	O
the	O
memory	O
performance	O
is	O
computed	O
by	O
dividing	O
the	O
processor	O
clock	O
rate	O
(	O
which	O
is	O
a	O
base	O
number	O
times	O
a	O
CPU	B-General_Concept
multiplier	O
,	O
for	O
instance	O
1.8GHz	O
is	O
most	O
likely	O
9×200MHz	O
)	O
by	O
a	O
fixed	O
integer	O
such	O
that	O
,	O
at	O
a	O
stock	O
clock	O
rate	O
,	O
the	O
RAM	B-Architecture
would	O
run	O
at	O
a	O
clock	O
rate	O
near	O
333MHz	O
.	O
</s>
<s>
Manipulating	O
elements	O
of	O
how	O
the	O
processor	O
clock	O
rate	O
is	O
set	O
(	O
usually	O
adjusting	O
the	O
multiplier	O
)	O
,	O
it	O
is	O
often	O
possible	O
to	O
overclock	B-Application
the	O
processor	O
a	O
small	O
amount	O
,	O
around	O
5-10	O
%	O
,	O
and	O
gain	O
a	O
small	O
increase	O
in	O
RAM	B-Architecture
clock	O
rate	O
and/or	O
reduction	O
in	O
RAM	B-Architecture
latency	O
timings	O
.	O
</s>
<s>
It	O
can	O
be	O
cheaper	O
to	O
purchase	O
a	O
lower	O
performance	O
component	O
and	O
overclock	B-Application
it	O
to	O
the	O
clock	O
rate	O
of	O
a	O
more	O
expensive	O
component	O
.	O
</s>
<s>
For	O
example	O
:	O
Microsoft	B-Application
Windows	I-Application
may	O
appear	O
to	O
work	O
with	O
no	O
problems	O
,	O
but	O
when	O
it	O
is	O
re-installed	O
or	O
upgraded	O
,	O
error	O
messages	O
may	O
be	O
received	O
such	O
as	O
a	O
"	O
file	O
copy	O
error	O
"	O
during	O
Windows	O
Setup	O
.	O
</s>
<s>
Warranties	O
may	O
be	O
voided	O
by	O
overclocking	B-Application
.	O
</s>
<s>
Exotic	O
cooling	O
methods	O
used	O
to	O
facilitate	O
overclocking	B-Application
such	O
as	O
water	O
cooling	O
are	O
more	O
likely	O
to	O
cause	O
damage	O
if	O
they	O
malfunction	O
.	O
</s>
<s>
Overclocking	B-Application
components	O
can	O
only	O
be	O
of	O
noticeable	O
benefit	O
if	O
the	O
component	O
is	O
on	O
the	O
critical	O
path	O
for	O
a	O
process	O
,	O
if	O
it	O
is	O
a	O
bottleneck	O
.	O
</s>
<s>
Overclocking	B-Application
a	O
CPU	B-General_Concept
will	O
not	O
noticeably	O
benefit	O
a	O
game	O
when	O
a	O
graphics	B-Device
card	I-Device
's	O
performance	O
is	O
the	O
"	O
bottleneck	O
"	O
of	O
the	O
game	O
.	O
</s>
<s>
Graphics	B-Device
cards	I-Device
can	O
also	O
be	O
overclocked	O
.	O
</s>
<s>
There	O
are	O
utilities	B-Application
to	O
achieve	O
this	O
,	O
such	O
as	O
EVGA	O
's	O
Precision	O
,	O
RivaTuner	B-Application
,	O
AMD	O
Overdrive	O
(	O
on	O
AMD	O
cards	O
only	O
)	O
,	O
MSI	B-Application
Afterburner	I-Application
,	O
Zotac	O
Firestorm	O
,	O
and	O
the	O
PEG	O
Link	O
Mode	O
on	O
Asus	O
motherboards	B-Device
.	O
</s>
<s>
Overclocking	B-Application
a	O
GPU	B-Architecture
will	O
often	O
yield	O
a	O
marked	O
increase	O
in	O
performance	O
in	O
synthetic	O
benchmarks	O
,	O
usually	O
reflected	O
in	O
game	O
performance	O
.	O
</s>
<s>
It	O
is	O
sometimes	O
possible	O
to	O
see	O
that	O
a	O
graphics	B-Device
card	I-Device
is	O
being	O
pushed	O
beyond	O
its	O
limits	O
before	O
any	O
permanent	O
damage	O
is	O
done	O
by	O
observing	O
on-screen	O
artifacts	O
or	O
unexpected	O
system	O
crashes	O
.	O
</s>
<s>
It	O
is	O
common	O
to	O
run	O
into	O
one	O
of	O
those	O
problems	O
when	O
overclocking	B-Application
graphics	B-Device
cards	I-Device
;	O
both	O
symptoms	O
at	O
the	O
same	O
time	O
usually	O
means	O
that	O
the	O
card	O
is	O
severely	O
pushed	O
beyond	O
its	O
heat	O
,	O
clock	O
rate	O
,	O
and/or	O
voltage	O
limits	O
,	O
however	O
if	O
seen	O
when	O
not	O
overclocked	O
,	O
they	O
indicate	O
a	O
faulty	O
card	O
.	O
</s>
<s>
After	O
a	O
reboot	O
,	O
video	O
settings	O
are	O
reset	O
to	O
standard	O
values	O
stored	O
in	O
the	O
graphics	B-Device
card	I-Device
firmware	B-Application
,	O
and	O
the	O
maximum	O
clock	O
rate	O
of	O
that	O
specific	O
card	O
is	O
now	O
deducted	O
.	O
</s>
<s>
Some	O
overclockers	B-Application
apply	O
a	O
potentiometer	B-Device
to	O
the	O
graphics	B-Device
card	I-Device
to	O
manually	O
adjust	O
the	O
voltage	O
(	O
which	O
usually	O
invalidates	O
the	O
warranty	O
)	O
.	O
</s>
<s>
This	O
allows	O
for	O
finer	O
adjustments	O
,	O
as	O
overclocking	B-Application
software	O
for	O
graphics	B-Device
cards	I-Device
can	O
only	O
go	O
so	O
far	O
.	O
</s>
<s>
Excessive	O
voltage	O
increases	O
may	O
damage	O
or	O
destroy	O
components	O
on	O
the	O
graphics	B-Device
card	I-Device
or	O
the	O
entire	O
graphics	B-Device
card	I-Device
itself	O
(	O
practically	O
speaking	O
)	O
.	O
</s>
<s>
Flashing	O
and	O
unlocking	O
can	O
be	O
used	O
to	O
improve	O
the	O
performance	O
of	O
a	O
video	B-Device
card	I-Device
,	O
without	O
technically	O
overclocking	B-Application
(	O
but	O
is	O
much	O
riskier	O
than	O
overclocking	B-Application
just	O
through	O
software	O
)	O
.	O
</s>
<s>
Flashing	O
refers	O
to	O
using	O
the	O
firmware	B-Application
of	O
a	O
different	O
card	O
with	O
the	O
same	O
(	O
or	O
sometimes	O
similar	O
)	O
core	O
and	O
compatible	O
firmware	B-Application
,	O
effectively	O
making	O
it	O
a	O
higher	O
model	O
card	O
;	O
it	O
can	O
be	O
difficult	O
,	O
and	O
may	O
be	O
irreversible	O
.	O
</s>
<s>
Sometimes	O
standalone	B-Application
software	I-Application
to	O
modify	O
the	O
firmware	B-Application
files	O
can	O
be	O
found	O
,	O
e.g.	O
</s>
<s>
NiBiTor	O
(	O
GeForce	B-Application
6/7	O
series	O
are	O
well	O
regarded	O
in	O
this	O
aspect	O
)	O
,	O
without	O
using	O
firmware	B-Application
for	O
a	O
better	O
model	O
video	B-Device
card	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
video	B-Device
cards	I-Device
with	O
3D	B-Architecture
accelerators	I-Architecture
(	O
most	O
,	O
)	O
have	O
two	O
voltage	O
and	O
clock	O
rate	O
settings	O
,	O
one	O
for	O
2D	O
and	O
one	O
for	O
3D	O
,	O
but	O
were	O
designed	O
to	O
operate	O
with	O
three	O
voltage	O
stages	O
,	O
the	O
third	O
being	O
somewhere	O
between	O
the	O
aforementioned	O
two	O
,	O
serving	O
as	O
a	O
fallback	O
when	O
the	O
card	O
overheats	O
or	O
as	O
a	O
middle-stage	O
when	O
going	O
from	O
2D	O
to	O
3D	O
operation	O
mode	O
.	O
</s>
<s>
Therefore	O
,	O
it	O
could	O
be	O
wise	O
to	O
set	O
this	O
middle-stage	O
prior	O
to	O
"	O
serious	O
"	O
overclocking	B-Application
,	O
specifically	O
because	O
of	O
this	O
fallback	O
ability	O
;	O
the	O
card	O
can	O
drop	O
down	O
to	O
this	O
clock	O
rate	O
,	O
reducing	O
by	O
a	O
few	O
(	O
or	O
sometimes	O
a	O
few	O
dozen	O
,	O
depending	O
on	O
the	O
setting	O
)	O
percent	O
of	O
its	O
efficiency	O
and	O
cool	O
down	O
,	O
without	O
dropping	O
out	O
of	O
3D	O
mode	O
(	O
and	O
afterwards	O
return	O
to	O
the	O
desired	O
high	O
performance	O
clock	O
and	O
voltage	O
settings	O
)	O
.	O
</s>
<s>
Some	O
cards	O
have	O
abilities	O
not	O
directly	O
connected	O
with	O
overclocking	B-Application
.	O
</s>
<s>
For	O
example	O
,	O
Nvidia	O
's	O
GeForce	B-Application
6600GT	I-Application
(	O
AGP	B-Architecture
flavor	O
)	O
has	O
a	O
temperature	O
monitor	O
used	O
internally	O
by	O
the	O
card	O
,	O
invisible	O
to	O
the	O
user	O
if	O
standard	O
firmware	B-Application
is	O
used	O
.	O
</s>
<s>
Modifying	O
the	O
firmware	B-Application
can	O
display	O
a	O
'	O
Temperature	O
 '	O
tab	O
.	O
</s>
<s>
Unlocking	O
refers	O
to	O
enabling	O
extra	O
pipelines	B-General_Concept
or	O
pixel	O
shaders	O
.	O
</s>
<s>
The	O
6800LE	O
,	O
the	O
6800GS	O
and	O
6800	O
(	O
AGP	B-Architecture
models	O
only	O
)	O
were	O
some	O
of	O
the	O
first	O
cards	O
to	O
benefit	O
from	O
unlocking	O
.	O
</s>
<s>
While	O
these	O
models	O
have	O
either	O
8	O
or	O
12	O
pipes	O
enabled	O
,	O
they	O
share	O
the	O
same	O
16x6	O
GPU	B-Architecture
core	O
as	O
a	O
6800GT	O
or	O
Ultra	O
,	O
but	O
pipelines	B-General_Concept
and	O
shaders	O
beyond	O
those	O
specified	O
are	O
disabled	O
;	O
the	O
GPU	B-Architecture
may	O
be	O
fully	O
functional	O
,	O
or	O
may	O
have	O
been	O
found	O
to	O
have	O
faults	O
which	O
do	O
not	O
affect	O
operation	O
at	O
the	O
lower	O
specification	O
.	O
</s>
<s>
GPUs	B-Architecture
found	O
to	O
be	O
fully	O
functional	O
can	O
be	O
unlocked	O
successfully	O
,	O
although	O
it	O
is	O
not	O
possible	O
to	O
be	O
sure	O
that	O
there	O
are	O
undiscovered	O
faults	O
;	O
in	O
the	O
worst	O
case	O
the	O
card	O
may	O
become	O
permanently	O
unusable	O
.	O
</s>
<s>
Overclocked	O
processors	B-General_Concept
first	O
became	O
commercially	O
available	O
in	O
1983	O
,	O
when	O
AMD	O
sold	O
an	O
overclocked	O
version	O
of	O
the	O
Intel	B-Device
8088	I-Device
CPU	B-General_Concept
.	O
</s>
