Editing Overclocking (section)

=== Cooling ===
{{Main|Computer cooling}}
[[Image:Copper heat sink with pipes.jpg|thumb|High quality [[heat sink]]s are often made of [[copper]].]]

All [[Electrical network|electronic circuits]] produce heat generated by the movement of electric current. As clock frequencies in [[digital circuit]]s and voltage applied increase, the heat generated by components running at the higher performance levels also increases. The relationship between clock frequencies and [[thermal design power]] (TDP) are linear. However, there is a limit to the maximum frequency which is called a "wall". To overcome this issue, overclockers raise the chip voltage to increase the overclocking potential. Voltage increases power consumption and consequently heat generation significantly (proportionally to the square of the voltage in a linear circuit, for example); this requires more cooling to avoid damaging the hardware by overheating. In addition, some digital circuits slow down at high temperatures due to changes in [[MOSFET]] device characteristics. Conversely, the overclocker may decide to ''decrease'' the chip voltage while overclocking (a process known as undervolting), to reduce heat emissions while performance remains optimal.

Stock cooling systems are designed for the amount of power produced during non-overclocked use; overclocked circuits can require more cooling, such as by powerful [[fan (mechanical)|fans]], larger [[heat sink]]s, [[heat pipe]]s and [[water cooling]]. Mass, shape, and material all influence the ability of a heatsink to dissipate heat. Efficient heatsinks are often made entirely of [[copper]], which has high [[thermal conductivity]], but is expensive.<ref name=Wainner38>{{cite book | title = The Book of Overclocking | first1 = Scott | last1 = Wainner | first2 = Robert |last2=Richmond | page = [https://archive.org/details/bookofoverclocki0000wain/page/38 38] | isbn = 978-1-886411-76-0 | publisher = No Starch Press | year = 2003 | url = https://archive.org/details/bookofoverclocki0000wain/page/38 }}</ref> [[Aluminium]] is more widely used; it has good thermal characteristics, though not as good as copper, and is significantly cheaper. Cheaper materials such as steel do not have good thermal characteristics. [[Heat pipe]]s can be used to improve conductivity. Many heatsinks combine two or more materials to achieve a balance between performance and cost.<ref name=Wainner38/>

[[File:DIY PC watercooling T-Line.JPG|Interior of a water-cooled computer, showing CPU [[water block]], tubing, and pump|left|thumb]]

Water cooling carries [[waste heat]] to a [[radiator]]. [[Thermoelectric cooling]] devices which actually refrigerate using the [[Peltier effect]] can help with high [[thermal design power]] (TDP) processors made by Intel and AMD in the early twenty-first century. Thermoelectric cooling devices create temperature differences between two plates by running an [[electric current]] through the plates. This method of cooling is highly effective, but itself generates significant heat elsewhere which must be carried away, often by a convection-based heatsink or a [[water cooling#Computer usage|water cooling]] system.

[[Image:2007TaipeiITMonth IntelOCLiveTest Overclocking-6.jpg|right|thumb|[[Liquid nitrogen]] may be used for cooling an overclocked system, when an extreme measure of cooling is needed.]]

Other cooling methods are [[forced convection]] and [[phase transition]] cooling which is used in [[refrigerator]]s and can be adapted for computer use. [[Liquid nitrogen]], [[liquid helium]], and [[dry ice]] are used as coolants in extreme cases,<ref name=Wainner44>{{cite book | title = The Book of Overclocking | first1 = Scott | last1 = Wainner | first2 = Robert |last2=Richmond | page = [https://archive.org/details/bookofoverclocki0000wain/page/44 44] | isbn = 978-1-886411-76-0 | publisher = No Starch Press | year = 2003 | url = https://archive.org/details/bookofoverclocki0000wain/page/44 }}</ref> such as record-setting attempts or one-off experiments rather than cooling an everyday system. In June 2006, [[IBM]] and [[Georgia Institute of Technology]] jointly announced a new record in silicon-based chip [[clock rate]] (the rate a transistor can be switched at, not the CPU clock rate<ref>{{cite web|last=Stokes|first=Jon|title=IBM's 500GHz processor? Not so fast…|url=https://arstechnica.com/uncategorized/2006/06/7117-2/|website=Ars Technica|date=22 June 2006|access-date=14 June 2017|archive-date=20 October 2017|archive-url=https://web.archive.org/web/20171020190922/https://arstechnica.com/uncategorized/2006/06/7117-2/|url-status=live}}</ref>) above 500&nbsp;GHz, which was done by cooling the chip to {{Convert|4.5|K|C F|1|lk=on}} using liquid helium.<ref>{{cite web| last = Toon| first = John| date = 20 June 2006| url = http://gtresearchnews.gatech.edu/georgia-techibm-team-demonstrates-first-500-ghz-silicon-germanium-transistors/| title = Georgia Tech/IBM Announce New Chip Speed Record| publisher = Georgia Institute of Technology| access-date = 2 February 2009| url-status = dead| archive-url = https://web.archive.org/web/20100701230256/http://gtresearchnews.gatech.edu/georgia-techibm-team-demonstrates-first-500-ghz-silicon-germanium-transistors/| archive-date = 1 July 2010}}</ref> Set in November 2012, the CPU Frequency World Record is 9008.82&nbsp;MHz as of December 2022.<ref>{{cite web |title=Intel Core i9 13900K Breaks the CPU Frequency World Record |url=https://valid.x86.fr/t14i1f |url-status=live |archive-url=https://web.archive.org/web/20180302225606/https://valid.x86.fr/t14i1f |archive-date=2018-03-02 |access-date=2022-12-09}}</ref> These extreme methods are generally impractical in the long term, as they require refilling reservoirs of vaporizing coolant, and [[condensation]] can form on chilled components.<ref name=Wainner44/> Moreover, [[silicon]]-based [[junction gate field-effect transistor]]s (JFET) will degrade below temperatures of roughly {{convert|100|K|C F|0}} and eventually cease to function or "freeze out" at {{convert|40|K|C F|0}} since the silicon ceases to be semiconducting,<ref>{{cite web | title = Extreme-Temperature Electronics: Tutorial – Part 3 | url = http://www.extremetemperatureelectronics.com/tutorial3.html | year = 2003 | access-date = 2007-11-04 | archive-date = 2012-03-06 | archive-url = https://web.archive.org/web/20120306214055/http://www.extremetemperatureelectronics.com/tutorial3.html | url-status = live }}</ref> so using extremely cold coolants may cause devices to fail. [[Blowtorch]] is used to temporarily raise temperature to issues of over-cooling when not desirable.<ref>{{Cite news |author1=Wes Fenlon |date=2017-06-09 |title=Overclocking a CPU to 7 GHz with the science of liquid nitrogen |language=en |work=PC Gamer |url=https://www.pcgamer.com/overclocking-a-cpu-to-7-ghz-with-the-science-of-liquid-nitrogen/ |access-date=2023-11-12}}</ref><ref>{{Cite web |date=2019-08-08 |title=Overclocking to 7GHz takes more than just liquid nitrogen |url=https://www.engadget.com/2017-06-04-gskill-hwbot-overclocking-workshop-7ghz-computex.html |access-date=2023-11-12 |website=Engadget |language=en-US}}</ref>

Submersion cooling, used by the [[Cray-2]] [[supercomputer]], involves sinking a part of computer system directly into a chilled liquid that is thermally conductive but has low [[electrical conductivity]]. The advantage of this technique is that no condensation can form on components.<ref name=Wainner48/> A good submersion liquid is [[Fluorinert]] made by [[3M]], which is expensive. Another option is [[mineral oil]], but impurities such as those in water might cause it to conduct electricity.<ref name=Wainner48>{{cite book | title = The Book of Overclocking | first = Scott | last = Wainner | author2 = Robert Richmond | page = [https://archive.org/details/bookofoverclocki0000wain/page/48 48] | isbn = 978-1-886411-76-0 | publisher = No Starch Press | year = 2003 | url = https://archive.org/details/bookofoverclocki0000wain/page/48 }}</ref>

Amateur overclocking enthusiasts have used a mixture of [[dry ice]] and a solvent with a low freezing point, such as [[acetone]] or [[isopropyl alcohol]].<ref>{{cite web |url=https://www.techpowerup.com/forums/threads/overclocking-with-dry-ice.101545/ |title=overclocking with dry ice! |work=TechPowerUp Forums |date=August 13, 2009 |access-date=January 7, 2020 |archive-date=December 7, 2019 |archive-url=https://web.archive.org/web/20191207134408/https://www.techpowerup.com/forums/threads/overclocking-with-dry-ice.101545/ |url-status=live }}</ref> This [[cooling bath]], often used in laboratories, achieves a temperature of {{convert|−78|C}}.<ref>[http://chemwiki.ucdavis.edu/VV_Lab_Techniques/Cooling_baths Cooling baths – ChemWiki] {{Webarchive|url=https://web.archive.org/web/20120828144459/http://chemwiki.ucdavis.edu/VV_Lab_Techniques/Cooling_baths |date=2012-08-28 }}. Chemwiki.ucdavis.edu. Retrieved on 2013-06-17.</ref> However, this practice is discouraged due to its safety risks; the solvents are flammable and volatile, and dry ice can cause [[frostbite]] (through contact with exposed skin) and suffocation (due to the large volume of [[carbon dioxide]] generated when it sublimes).