View source for Cool'n'Quiet

{{short description|Power saving mode of modern processors by Advanced Micro Devices}}
{{Infobox computer hardware
| name         = AMD Cool'n'Quiet
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| designfirm   = [[Advanced Micro Devices]]
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| introduced   = 2002
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| type         = [[Dynamic frequency scaling]]
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'''AMD Cool'n'Quiet''' is a [[central processing unit|CPU]] [[dynamic frequency scaling]] and power saving technology introduced by [[AMD]] with its [[Athlon XP]] processor line.<ref>{{cite web |title=AMD Offering Version of PowerNow! For Athlon XP |date=25 January 2002 |url=https://www.extremetech.com/extreme/72736-amd-offering-version-of-powernow-for-athlon-xp}}</ref> It works by reducing the processor's [[clock rate]] and [[voltage]] when the processor is idle. The aim of this technology is to reduce overall [[power consumption]] and lower heat generation, allowing for slower (thus [[Quiet PC|quieter]]) [[computer fan|cooling fan]] operation. The objectives of cooler and quieter result in the name Cool'n'Quiet. The technology is similar to [[Intel|Intel's]] [[SpeedStep]] and AMD's own [[PowerNow!]], which were developed with the aim of increasing laptop battery life by reducing power consumption.

Due to their different usage, ''Cool'n'Quiet'' refers to desktop and server chips, while ''PowerNow!'' is used for mobile chips; the technologies are similar but not identical. This technology was also introduced on "e-stepping" [[Opteron]]s, however it is called ''Optimized Power Management'', which is essentially a re-tooled Cool'n'Quiet scheme designed to work with [[registered memory]].

''Cool'n'Quiet'' is fully supported in the [[Linux kernel]] from version 2.6.18 onward (using the powernow-k8 driver) and FreeBSD from 6.0-CURRENT onward.<ref>{{cite web|url=https://www.kernel.org/pub/linux/utils/kernel/cpufreq/hardware.html |title=Linux kernel CPUfreq subsystem – hardware |publisher=The Linux Kernel Archives |accessdate=2007-08-18 |url-status=dead |archiveurl=https://web.archive.org/web/20110721105807/http://www.kernel.org/pub/linux/utils/kernel/cpufreq/hardware.html |archivedate=July 21, 2011 }}</ref><ref>{{cite web |url=http://www.onlamp.com/pub/a/bsd/2008/02/26/whats-new-in-freebsd-70.html?page=2 |title=What's New in FreeBSD 7.0 |publisher=O'Reilly Media, Inc. |date=2008-02-26 |accessdate=2008-05-19 |archive-date=2008-03-29 |archive-url=https://web.archive.org/web/20080329081941/http://www.onlamp.com/pub/a/bsd/2008/02/26/whats-new-in-freebsd-70.html?page=2 |url-status=dead }}</ref>

==Implementation==
In-order to take advantage of Cool'n'Quiet Technology in Microsoft's Operating Systems:<ref>{{cite web |url=http://www.asus.com/999/html/events/mb/cnq.htm |archive-url=https://archive.today/20120719223708/http://www.asus.com/999/html/events/mb/cnq.htm |url-status=dead |archive-date=2012-07-19 |title=Implementing Cool'n'Quiet |publisher=Advanced Micro Devices, Inc. }}</ref>
* '''Cool'n'Quiet''' should be Enabled in system BIOS
* In Windows XP and 2000: Operating Systems "'''Minimal Power Management'''" profile must be active in "'''Power Schemes'''". A PPM driver was also released by AMD that facilitates this.<ref>{{cite web|url=https://www.techspot.com/drivers/driver/file/information/14442/|title=AMD Processor Driver 1.3.2.0053 for Windows XP/Server 2003 32/64-bit|publisher=Techspot |date=November 2009 |accessdate=2021-12-26}}</ref>
* In Windows Vista and 7: "'''Minimum processor state'''" found in "'''Processor Power Management'''" of "'''Advanced Power Settings'''" should be lower than "'''100%'''".
Also In Windows Vista and 7 the "'''Power Saver'''" power profile allows much lower power state (frequency and voltage) than in the "'''High Performance'''" power state.

Unlike Windows XP, Windows Vista only supports Cool'n'Quiet on motherboards that support [[Advanced Configuration and Power Interface|ACPI]] 2.0 or later.

With earlier versions of Windows, processor drivers along with Cool'n'Quiet software also need to be installed. The latest version is 1.3.2.0.<ref>{{cite web |url=https://www.amd.com/us-en/assets/content_type/DownloadableAssets/Cool_N_Quiet_Installation_Guide3.pdf |title=Cool'n'Quiet Technology Installation Guide for AMD Athlon 64 Processor Based Systems |publisher=Advanced Micro Devices, Inc. |date=June 2004 |accessdate=2007-08-18 |archiveurl = https://web.archive.org/web/20070409045621/http://www.amd.com/us-en/assets/content_type/DownloadableAssets/Cool_N_Quiet_Installation_Guide3.pdf <!-- Bot retrieved archive --> |archivedate = 2007-04-09}}</ref>

==Third party utilities==
In addition to the CPU drivers offered by AMD, several motherboard manufacturers have released software to give the end user more control over the ''Cool 'n' Quiet'' feature, as well as the other new features of AMD processors and chipsets. Using these applications, one can even control the CPU voltage explicitly.

# [http://phenommsrtweake.sourceforge.net/ PhenomMsrTweaker (SourceForge link)]
# [[RMClock]]

==Processors supporting Cool'n'Quiet==
{{Expand list|date=October 2017}}
* [[Athlon XP]]
* [[Athlon 64]] and [[Athlon 64 X2|X2]] – all models
* Athlon 64 FX – FX-53 ([[Socket 939]] only) and higher
* [[Athlon 64 FX|FX]] (Socket 942)
* [[Athlon II]] – all models
* [[Sempron]] – [[Socket 754]]: 3000+ and higher; [[Socket AM2]]: 3200+ and higher
* Opteron – E-stepping and higher, branded as ''Optimized Power Management''
* [[Phenom (processor)|Phenom]] – all versions support Cool'n'Quiet 2.0
* [[Phenom II]] – supports Cool'n'Quiet 3.0
* some of the [[AMD Accelerated Processing Unit|APUs]]
* [[Ryzen]] – 3, 5, 7, and 9 all models support Cool ‘n’ Quiet
* [[EPYC]]

==See also==
* [[Dynamic frequency scaling]]
Power Saving Technologies:
* [[PowerNow!|AMD PowerNow!]] (laptop CPUs)
* [[AMD PowerTune]]/[[AMD PowerPlay]] (graphics)
* [[AMD Hybrid Graphics#PowerXpress|AMD PowerXpress]] (multi-graphics)
* [[SpeedStep|Intel SpeedStep]] (CPUs)
Performance Boosting Technologies:
* [[AMD Turbo Core]] (CPUs)
* [[Intel Turbo Boost]] (CPUs)

==References==
{{reflist}}

==External links==
* [https://archive.today/20130116192135/http://www.amd.com/us/products/technologies/cool-n-quiet/ AMD Cool'n'Quiet 2002]
* [http://phenommsrtweake.sourceforge.net/ Phenommsrtweaker]
* [http://mytechencounters.wordpress.com/2010/03/15/overclock-your-phenom-cpu-and-save-power-simultaneously/ Custom Cool'n'Quiet]

{{AMD technology}}
{{Computer processor power management technologies}}

[[Category:Computer hardware tuning]]
[[Category:AMD technologies]]
[[Category:Clock signal]]
[[Category:2002 introductions]]
[[Category:X86 architecture]]