197:(AMD) have defined TDP as the maximum heat generation for thermally significant periods, while running worst-case non-synthetic workloads; thus, TDP is not reflecting the actual maximum power of the processor. This ensures the computer will be able to handle essentially all applications without exceeding its thermal envelope, or requiring a cooling system for the maximum theoretical power (which would cost more but in favor of extra headroom for processing power).
646:
485:) emanates at a micro-level in transistors. Small amounts of currents are always flowing between the differently doped parts of the transistor. The magnitude of these currents depend on the state of the transistor, its dimensions, physical properties and sometimes temperature. The total amount of leakage currents tends to inflate for increasing temperature and decreasing transistor sizes.
31:
343:
The dynamic power consumption originates from the activity of logic gates inside a CPU. When the logic gates toggle, energy is flowing as the capacitors inside them are charged and discharged. The dynamic power consumed by a CPU is approximately proportional to the CPU frequency, and to the square of
816:
In Intel's case, a specified chip's TDP has less to do with the amount of power a chip needs to use (or can use) and more to do with the amount of power the computer's fan and heatsink need to be able to dissipate while the chip is under sustained load. Actual power usage can be higher or (much)
488:
Both dynamic and short-circuit power consumption are dependent on the clock frequency, while the leakage current is dependent on the CPU supply voltage. It has been shown that the energy consumption of a program shows convex energy behavior, meaning that there exists an optimal CPU frequency at
617:
or multi-process manner to take full advantage of such hardware. Many multi-threaded development paradigms introduce overhead, and will not see a linear increase in speed when compared to the number of processors. This is particularly true while accessing shared or dependent resources, due to
415:
When logic gates toggle, some transistors inside may change states. As this takes a finite amount of time, it may happen that for a very brief amount of time some transistors are conducting simultaneously. A direct path between the source and ground then results in some short-circuit power loss
633:
Processors can be damaged from overheating, but vendors protect processors with operational safeguards such as throttling and automatic shutdown. When a core exceeds the set throttle temperature, processors can reduce power to maintain a safe temperature level and if the processor is unable to
236:
have been instituted in personal computers for when they are idle, the overall consumption of today's high-performance CPUs is considerable. This is in strong contrast with the much lower energy consumption of CPUs designed for low-power devices.
1111:
204:
features to reduce energy use, other components, such as the motherboard and chipset, take up a larger proportion of the computer's energy. In applications where the computer is often heavily loaded, such as scientific computing,
1125:
173:
For example, the
Pentium 4 2.8 GHz has a 68.4 W typical thermal power and 85 W maximum thermal power. When the CPU is idle, it will draw far less than the typical thermal power.
339:
877:
De
Vogeleer, Karel; Memmi, Gerard; Jouvelot, Pierre; Coelho, Fabien (2013-09-09). "The Energy/Frequency Convexity Rule: Modeling and Experimental Validation on Mobile Devices".
396:
549:, which can be thought of as reducing the capacitance switched on each clock tick, or can be thought of as locally reducing the clock frequency in some sections of the chip.
609:, so that single-threaded code executed faster on newer processors with no modification. More recently, in order to manage CPU power dissipation, processor makers favor
200:
In many applications, the CPU and other components are idle much of the time, so idle power contributes significantly to overall system power usage. When the CPU uses
483:
444:
245:
There are several factors contributing to the CPU power consumption; they include dynamic power consumption, short-circuit power consumption, and power loss due to
552:
Various techniques to reduce the switching activity – number of transitions the CPU drives into off-chip data buses, such as non-multiplexed
788:
Thermal Design Power (TDP) should be used for processor thermal solution design targets. The TDP is not the maximum power that the processor can dissipate.
665:
531:
that replace PCB traces between two chips with relatively lower-capacitance on-chip metal interconnect between two sections of a single integrated chip;
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625:
Recently, IBM has been exploring ways to distribute computing power more efficiently by mimicking the distributional properties of the human brain.
899:
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As a processor model's design matures, smaller transistors, lower-voltage structures, and design experience may reduce energy consumption.
107:, consume power in the order of tens to hundreds of watts. Some other CPU implementations use very little power; for example, the CPUs in
801:
581:
Recycling at least some of that energy stored in the capacitors (rather than dissipating it as heat in transistors) –
1007:
Al-Khatib, Zaid; Abdi, Samar (2015-04-13). "Operand-Value-Based
Modeling of Dynamic Energy Consumption of Soft Processors in FPGA".
916:
Basu, K.; Choudhary, A.; Pisharath, J.; Kandemir, M. (2002). "Power protocol: Reducing power dissipation on off-chip data buses".
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660:
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maintain a safe operating temperature through throttling actions, it will automatically shut down to prevent permanent damage.
134:
usually reduces energy consumption; it is also possible to undervolt the microprocessor while keeping the clock rate the same.
606:
817:
lower than TDP, but the figure is intended to give guidance to engineers designing cooling solutions for their products.
592:
clusters of instructions using common components, the CPU power used to run an application can be significantly reduced.
225:
80:
1178:
1114:. Ballistic Research Laboratories. Reportno. 971. United States Department of Commerce Office of Technical Services.
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446:). The magnitude of this power is dependent on the logic gate, and is rather complex to model on a macro level.
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is a major consideration of nearly all CPU manufacturers to date. Historically, early CPUs implemented with
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194:
130:
For a given CPU core, energy usage will scale up as its clock rate increases. Reducing the clock rate or
1133:
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K. Moiseev, A. Kolodny and S. Wimer (September 2008). "Timing-aware power-optimal ordering of signals".
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35th Annual IEEE/ACM International
Symposium on Microarchitecture, 2002. (MICRO-35). Proceedings
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CPU Reference for all vendors. Process node, die size, speed, power, instruction set, etc.
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17:
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Low Power
Architecture Design and Compilation Techniques for High-Performance Processors
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contention. This effect becomes more noticeable as the number of processors increases.
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671:
614:
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1041:
772:
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1011:. Lecture Notes in Computer Science. Vol. 9040. Springer, Cham. pp. 65–76.
830:"Enhanced Intel SpeedStep Technology for the Intel Pentium M Processor (White Paper)"
517:
84:
1207:
993:
958:
1179:
https://web.archive.org/web/20090216190358/http://mbsg.intel.com/mbsg/glossary.aspx
696:
578:
Layering heat-conduction zones within the CPU framework ("Christmassing the Gate").
557:
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142:
141:, each of which uses power. Turning unused areas off saves energy, such as through
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Processor manufacturers usually release two power consumption numbers for a CPU:
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209:(how much computing the CPU does per unit of energy) becomes more significant.
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1042:"The Free Lunch Is Over: A Fundamental Turn Toward Concurrency in Software"
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Power consumption can be reduced in several ways, including the following:
30:
737:
Zhang, Yifan; Liu, Yunxin; Zhuang, Li; Liu, Xuanzhe; Zhao, Feng; Li, Qun.
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Historically, processor manufacturers consistently delivered increases in
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may consume only a few milliwatts or even as little as a few microwatts.
92:
1154:
http://developer.intel.com/design/itanium2/documentation.htm#datasheets
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Optimizing machine code - by implementing compiler optimizations that
212:
CPUs typically use a significant portion of the power consumed by the
232:'s backlight also uses a significant portion of overall power. While
104:
1223:
1093:"Frequently Asked Questions About Temperature for Intel® Processors"
905:(Report). Advanced Computer Architecture Laboratory. ACAL-TR-94-01.
1220: – online calculation tool for server energy costs
883:
29:
182:
112:
54:
1217:
229:
802:"The technical details behind Intel's 7 Watt Ivy Bridge CPUs"
126:
There are a number of engineering reasons for this pattern:
1184:
http://download.intel.com/design/Xeon/datashts/25213506.pdf
1112:"A Survey of Domestic Electronic Digital Computing Systems"
974:
ACM Transactions on Design
Automation of Electronic Systems
159:, which is measured under normal load (for instance, AMD's
1189:
http://www.intel.com/Assets/en_US/PDF/datasheet/313079.pdf
898:
Su, Ching-Long; Tsui, Chi-Ying; Despain, Alvin M. (1994).
1169:
http://www.intel.com/design/intarch/prodbref/27331106.pdf
1164:
http://www.intel.com/design/mobile/datashts/24297301.pdf
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such as power protocol. Sometimes an "activity factor" (
489:
which energy consumption is minimal for the work done.
1195:
http://support.amd.com/us/Processor_TechDocs/43374.pdf
575:
Sacrificing transistor density for higher frequencies.
739:
Accurate CPU Power
Modeling for Multicore Smartphones
613:
chip designs, thus software needs to be written in a
572:) is put into the above equation to reflect activity.
527:
Capacitance reduction – increasingly
455:
422:
352:
257:
1159:
http://www.intel.com/pressroom/kits/quickreffam.htm
1174:http://www.via.com.tw/en/products/processors/c7-d/
477:
438:
390:
333:
334:{\displaystyle P_{cpu}=P_{dyn}+P_{sc}+P_{leak}}
27:Production of waste heat by computer processors
754:"Undervolting and Overclocking on Ivy Bridge"
597:Clock frequencies and multi-core chip designs
8:
741:(Report). Microsoft Research. MSR-TR-2015-9.
169:, which is measured under a worst-case load
53:, and dissipate this energy in the form of
666:Advanced Configuration and Power Interface
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547:globally asynchronous locally synchronous
460:
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863:Jan M. Rabaey; Massoud Pedram; editors.
449:Power consumption due to leakage power (
729:
1142:
1131:
516:Frequency reduction –
181:(TDP), which is the maximum amount of
1224:For specification on Intel processors
7:
1067:"IBM demos cognitive computer chips"
501:Voltage reduction –
137:New features generally require more
91:consumed power on the order of many
1213:Processor Electrical Specifications
404:is the switched load capacitance,
95:. Current CPUs in general-purpose
79:Designing CPUs that perform tasks
25:
800:Cunningham, Andrew (2013-01-14).
43:processing unit power dissipation
1065:Johnson, R. Colin (2011-08-18).
1009:Applied Reconfigurable Computing
865:"Low Power Design Methodologies"
644:
216:. Other major uses include fast
185:generated by the CPU, which the
846:from the original on 2015-08-12
661:Autonomous peripheral operation
391:{\displaystyle P_{dyn}=CV^{2}f}
1:
607:instruction-level parallelism
585:, energy recovery logic, etc.
189:in a computer is required to
1231:, 2001-04-15, by Paul DeMone
1017:10.1007/978-3-319-16214-0_6
773:"Athlon 64 for Quiet Power"
752:Cutress, Ian (2012-04-23).
247:transistor leakage currents
115:of electricity, while some
39:Processor power dissipation
1266:
941:10.1109/MICRO.2002.1176262
72:
18:CPU electrical consumption
771:Chin, Mike (2004-06-15).
522:dynamic frequency scaling
222:graphics processing units
1110:Weik, Martin H. (1955).
478:{\displaystyle P_{leak}}
45:is the process in which
1245:Central processing unit
986:10.1145/1391962.1391973
507:dynamic voltage scaling
1141:Cite journal requires
479:
440:
439:{\displaystyle P_{sc}}
392:
335:
234:energy-saving features
195:Advanced Micro Devices
35:
1040:Sutter, Herb (2005).
687:Low-power electronics
629:Processor overheating
480:
441:
393:
336:
177:normally contain the
167:maximum thermal power
157:typical thermal power
111:often use just a few
33:
925:. pp. 345–355.
702:Performance per watt
682:IT energy management
566:value cache encoding
562:Gray code addressing
453:
420:
350:
255:
207:performance per watt
179:thermal design power
1229:Making x86 Run Cool
1121:2027/wu.89037555299
541:techniques such as
529:integrated circuits
63:electronic circuits
47:computer processors
34:Photos of heatsinks
1197:, pages 10 and 80.
1047:Dr. Dobb's Journal
777:silentpcreview.com
652:Electronics portal
475:
436:
388:
331:
228:. In laptops, the
193:. Both Intel and
97:personal computers
36:
1026:978-3-319-16213-3
950:978-0-7695-1859-6
837:Intel Corporation
583:adiabatic circuit
503:dual-voltage CPUs
344:the CPU voltage:
161:average CPU power
51:electrical energy
16:(Redirected from
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1134:cite journal
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806:Ars Technica
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781:. Retrieved
776:
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757:
747:
732:
697:Overclocking
632:
624:
600:
569:
558:bus encoding
543:clock gating
539:Power gating
511:undervolting
496:
487:
448:
414:
412:is voltage.
399:
346:
342:
251:
244:
211:
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143:clock gating
132:undervolting
125:
89:vacuum tubes
78:
75:Variable TDP
42:
38:
37:
980:(4): 1–17.
779:. p. 3
712:Dissipation
692:Moore's law
603:clock rates
554:address bus
218:video cards
139:transistors
85:overheating
81:efficiently
57:due to the
1239:Categories
1078:2011-10-01
850:2013-12-21
811:2013-01-14
783:2013-12-21
724:References
611:multi-core
175:Datasheets
99:, such as
73:See also:
59:resistance
1191:, page 12
927:CiteSeerX
884:1401.4655
590:schedules
493:Reduction
191:dissipate
93:kilowatts
1072:EE Times
994:18895687
959:18811466
841:Archived
717:PowerTOP
638:See also
560:such as
214:computer
119:used in
101:desktops
83:without
49:consume
241:Sources
105:laptops
61:in the
1023:
992:
957:
947:
929:
668:(ACPI)
535:, etc.
524:, etc.
513:, etc.
400:where
224:, and
990:S2CID
955:S2CID
923:(PDF)
903:(PDF)
879:arXiv
844:(PDF)
833:(PDF)
564:, or
113:watts
1147:help
1054:(3).
1021:ISBN
945:ISBN
620:lock
605:and
545:and
183:heat
103:and
55:heat
1116:hdl
1013:doi
982:doi
937:doi
230:LCD
41:or
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1132:{{
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429:s
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416:(
410:V
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386:f
381:2
377:V
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370:=
365:n
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310:+
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302:s
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294:+
289:n
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283:d
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275:=
270:u
267:p
264:c
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