<s>
Processor	B-General_Concept
power	I-General_Concept
dissipation	I-General_Concept
or	O
processing	O
unit	O
power	O
dissipation	O
is	O
the	O
process	O
in	O
which	O
computer	O
processors	O
consume	O
electrical	O
energy	O
,	O
and	O
dissipate	O
this	O
energy	O
in	O
the	O
form	O
of	O
heat	O
due	O
to	O
the	O
resistance	O
in	O
the	O
electronic	O
circuits	O
.	O
</s>
<s>
Current	O
CPUs	O
in	O
general-purpose	O
personal	B-Device
computers	I-Device
,	O
such	O
as	O
desktops	O
and	O
laptops	B-Device
,	O
consume	O
power	O
in	O
the	O
order	O
of	O
tens	O
to	O
hundreds	O
of	O
watts	O
.	O
</s>
<s>
Some	O
other	O
CPU	O
implementations	O
use	O
very	O
little	O
power	O
;	O
for	O
example	O
,	O
the	O
CPUs	O
in	O
mobile	O
phones	O
often	O
use	O
just	O
a	O
few	O
watts	O
of	O
electricity	O
,	O
while	O
some	O
microcontrollers	B-Architecture
used	O
in	O
embedded	B-Architecture
systems	I-Architecture
may	O
consume	O
only	O
a	O
few	O
milliwatts	O
or	O
even	O
as	O
little	O
as	O
a	O
few	O
microwatts	O
.	O
</s>
<s>
For	O
a	O
given	O
CPU	B-Architecture
core	I-Architecture
,	O
energy	O
usage	O
will	O
scale	O
up	O
as	O
its	O
clock	O
rate	O
increases	O
.	O
</s>
<s>
New	O
features	O
generally	O
require	O
more	O
transistors	B-Application
,	O
each	O
of	O
which	O
uses	O
power	O
.	O
</s>
<s>
As	O
a	O
processor	O
model	O
's	O
design	O
matures	O
,	O
smaller	O
transistors	B-Application
,	O
lower-voltage	O
structures	O
,	O
and	O
design	O
experience	O
may	O
reduce	O
energy	O
consumption	O
.	O
</s>
<s>
Datasheets	O
normally	O
contain	O
the	O
thermal	B-General_Concept
design	I-General_Concept
power	I-General_Concept
(	O
TDP	O
)	O
,	O
which	O
is	O
the	O
maximum	O
amount	O
of	O
heat	O
generated	O
by	O
the	O
CPU	O
,	O
which	O
the	O
cooling	B-General_Concept
system	I-General_Concept
in	O
a	O
computer	O
is	O
required	O
to	O
dissipate	O
.	O
</s>
<s>
This	O
ensures	O
the	O
computer	O
will	O
be	O
able	O
to	O
handle	O
essentially	O
all	O
applications	O
without	O
exceeding	O
its	O
thermal	O
envelope	O
,	O
or	O
requiring	O
a	O
cooling	B-General_Concept
system	I-General_Concept
for	O
the	O
maximum	O
theoretical	O
power	O
(	O
which	O
would	O
cost	O
more	O
but	O
in	O
favor	O
of	O
extra	O
headroom	O
for	O
processing	O
power	O
)	O
.	O
</s>
<s>
Other	O
major	O
uses	O
include	O
fast	O
video	B-Device
cards	I-Device
,	O
which	O
contain	O
graphics	B-Architecture
processing	I-Architecture
units	I-Architecture
,	O
and	O
power	O
supplies	O
.	O
</s>
<s>
In	O
laptops	B-Device
,	O
the	O
LCD	B-Device
's	O
backlight	O
also	O
uses	O
a	O
significant	O
portion	O
of	O
overall	O
power	O
.	O
</s>
<s>
While	O
energy-saving	O
features	O
have	O
been	O
instituted	O
in	O
personal	B-Device
computers	I-Device
for	O
when	O
they	O
are	O
idle	O
,	O
the	O
overall	O
consumption	O
of	O
today	O
's	O
high-performance	O
CPUs	O
is	O
considerable	O
.	O
</s>
