Editing Quiet PC

{{short description|Type of personal computer}}
{{Use American English|date=January 2025}}
[[File:Fanless CPU Cooler.jpg|thumb|A fanless CPU cooler based on [[heat pipe]] technology]]

A '''quiet''', '''silent''' or '''fanless PC''' is a [[personal computer]] that makes very little or no [[noise]]. Common uses for quiet PCs include video editing, sound mixing and [[home theater PC]]s, but noise reduction techniques can also be used to greatly reduce the noise from servers. There is currently no standard definition for a "quiet PC",<ref name=WhatisSilentPC>{{cite web| url = http://www.silentpcreview.com/article669-page1.html | title = What is a "Silent" Computer  | first = Michael ‘Mike’ | last = Chin |date=2006-09-21 |publisher=Silent PC Review (SPCR)|access-date=2008-10-10}}</ref> and the term is generally not used in a business context, but by individuals and the businesses catering to them.

A proposed general definition is that the sound emitted by such PCs should not exceed 30 [[Sound pressure|dB<sub>A</sub>]],<ref>{{cite web | url = http://www.devhardware.com/c/a/Computer-Systems/Fundamentals/3/ | title = Building the Perfect PC | access-date = 2008-10-10 | first1 = Robert Bruce | last1 = Thompson | first2 = Barbara Fritchman | last2 = Thompson | publisher = Dev hardware | date = 2004-12-01 | archive-date = 2008-11-19 | archive-url = https://web.archive.org/web/20081119231217/http://www.devhardware.com/c/a/Computer-Systems/Fundamentals/3/ | url-status = dead }}</ref> but in addition to the average [[sound pressure level]], the frequency spectrum and dynamics of the sound are important in determining if the sound of the computer is [[Psychoacoustics|noticed]].  Sounds with a smooth frequency spectrum (lacking audible tonal peaks), and little temporal variation are less likely to be noticed.  The character and amount of other noise in the environment also affects how much sound will be noticed or [[Psychoacoustics#Masking effects|masked]], so a computer may be quiet in relation to a particular environment or set of users.<ref name=WhatisSilentPC />

==History==
Prior to about 1975, all computers were typically large industrial/commercial machines, often in a centralized location with a dedicated room-sized cooling system. For these systems, noise was not an important issue.

The first [[home computer]]s, such as the [[Commodore 64]], were very low power and therefore could run fanless or, like the [[IBM PC]], with a low-speed fan only used to cool the power supply, so noise was seldom an issue.

By the mid-1990s as CPU [[clock speed]]s increased above 60&nbsp;MHz, "spot-cooling" was added by means of a fan over the CPU heatsink to blow air onto the processor. Over time, more fans were included to provide spot-cooling in more locations where heat dissipation was needed, including the [[3D graphics card]]s as they grew more powerful. Computer cases increasingly needed to add fans to extract heated air from the case, but unless very carefully designed, this would add more noise.
 
[[Energy Star]], in 1992, and similar programs led to the widespread adoption of [[sleep mode]] among consumer electronics, and the [[TCO Certified]] program promoted lower energy consumption.<ref>{{cite news |title=TCO takes the initiative in comparative product testing |access-date=2008-05-03 |date=2008-05-03 |url=http://www.boivie.se/index.php?page=2&lang=eng |archive-date=2007-07-23 |archive-url=https://web.archive.org/web/20070723060821/http://www.boivie.se/index.php?page=2&lang=eng |url-status=dead }}</ref> Both added features that allowed systems to only consume as much power as is needed at a particular moment and helped reduce power consumption. In a similar manner the first low-power and energy-conserving CPUs were developed for use in laptops but can be used in any machine to reduce power requirements, and hence noise.

==Causes of noise==
The main causes of PC noise are:
* Mechanical friction generated by disk drives and fan bearings
* Vibration from disk drives<ref>{{cite web|last1=JIANG|first1=LIXIN|title=Fundamentals of Harddisk Drive Acoustics|url=https://www.roush.com/wp-content/uploads/2015/09/Data-Storage.pdf|publisher=www.roush.com|access-date=3 April 2016}}</ref> and fans
* Air turbulence caused by obstructions in the flow of air 
* Air vortex effects from fan blade edges<ref>[https://en.wikibooks.org/wiki/Acoustics/Noise_from_Cooling_Fans#Noise_Generation_Mechanisms Noise Generation Mechanisms]</ref><ref>[http://www.jmcproducts.com/acoustic-noise/ "Acoustic noise"], jmcproducts.com</ref>
* [[Electromagnetically induced acoustic noise and vibration|Electrical whine]]: noise generated by electrical coils or transformers used in [[power supply unit (computer)|power supplies]], [[motherboard]]s, [[video cards]] or [[LCD monitors]].<ref name=SPCRLCDwhine>{{cite web | url = http://www.silentpcreview.com/stop_lcd_whine | title = How to stop the whining noise of your LCD monitor | first = Michael ‘Mike’ | last = Chin | publisher = SPCR | date = 2008-11-05 | access-date = 2008-11-05 | archive-date = 2008-11-08 | archive-url = https://web.archive.org/web/20081108044212/http://www.silentpcreview.com/stop_lcd_whine | url-status = dead }}</ref>

Many of these sources increase with the power of the computer. More or faster transistors use more power, which releases more heat. Increasing the rotation speed of fans to address this will (all things being equal) increase their noise. Similarly, increasing [[hard disk drive]]s' and [[optical disc drive]]s' rotation speeds increases [[Hard disk drive performance characteristics|performance]], but generally also vibration and bearing friction.

==Measuring noise==
Though standards do exist for measuring and reporting sound power output by such things as computer components, they are often ignored.<ref>{{cite web| url= http://www.silentpcreview.com/article121-page4.html| title= A Primer on Noise in Computing | publisher= SPCR | first = Michael ‘Mike’ | last = Chin|date= 2003-10-28|access-date = 2008-10-10}}</ref><ref>{{cite web| url= http://www.silentpcreview.com/article28-page1.html| title= Power Supply Fundamentals| first= Michael ‘Mike’| last= Chin| date= 2005-04-06| publisher= SPCR| access-date= 2008-10-10| archive-date= 2011-11-26| archive-url= https://web.archive.org/web/20111126201935/http://www.silentpcreview.com/article28-page1.html| url-status= dead}}</ref> Many manufacturers do not give sound power measurements.  Some report sound pressure measurements, but those that do often do not specify how sound pressure measurements were taken. Even such basic information as measurement distance is rarely reported. Without knowing how it was measured, it is not possible to verify these claims, and comparisons between such measurements (e.g. for product selection) are meaningless.  Comparative reviews, which test several devices under the same conditions, are more useful, but even then, an average sound pressure level is only one factor in determining which components will be perceived as quieter.<ref name=WhatisSilentPC />

==Noise reduction methods==
{{multiple image
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| footer     =Reducing noise with new CPU cooler
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[[File:Copper heat sink with pipes.jpg|thumb|This passive heat sink in a [[Power Mac G4]] relies on large surface areas.]]

===Common noise reduction methods===
* Use large, efficient [[heat sink]]s
* Incorporate [[heat pipe]]s, which have much higher effective thermal conductivity than solid copper
* Use fans with lower speeds and larger diameters
* Use fans with low bearing and motor noise
* Rather than constant-speed fans, use thermostatically controlled variable-speed fans that run at less than maximum speed, and thus run quieter most of the time
* Use an efficient [[power supply]] to minimize [[waste heat]]
* Use quieter models of hard drive
* Use solid state devices like [[compact flash]] or solid-state drives rather than traditional mechanical hard drives
* Use remote networked via [[Server Message Block|SMB]] or [[Network File System (protocol)|NFS]] rather than local disks
* Place a damping material such as [[Sorbothane]] around hard drives or other spinning items
* Use [[sound insulation]] material to absorb sound and dampen case resonance
* [[Water cooling]], although difficult to set up, may be useful in some situations

=== Low-cost methods <span class="anchor" id="ODD"></span>===
A number of methods exist for reducing computer noise at little or no added cost.
* [[Dynamic voltage scaling|Reduce CPU supply voltage]] ("undervolting"). Many of today's CPUs can run stably at their stock speed, or even with a slight overclock, at a reduced voltage, which reduces heat output. Power consumption is approximately proportional to ''V<sup>2</sup>·f'', that is, it varies linearly with the clock frequency and quadratically with the voltage.<ref>{{Citation |first=JM |last=Rabaey |title=Digital Integrated Circuits |publisher=Prentice Hall |year=1996}}.</ref> This means that even a small reduction in voltage can have a large effect in power consumption. Undervolting and underclocking can also be used with [[chipset]]s and GPUs.
* Enable [[Cool'n'Quiet]] for [[AMD]] CPUs or [[SpeedStep]] (also known as [[EIST]]) on [[Intel]] CPUs.
* Reduce fan speed. For newer computers, the speed of fans can be varied automatically, depending on how hot certain parts of the computer get. Lowering a DC fan motor's supply voltage will reduce its speed while making it quieter and lowering the amount of air the fan moves. Doing this arbitrarily could lead to components overheating; therefore, whenever performing hardware work it is advised to monitor the temperature of system components. Fans with [[Molex connector]]s can be modified easily.<ref name=7vTrick>{{cite web |url=http://www.silentpcreview.com/article6-page1.html |title=Get 12V, 7V or 5V for your Fans |publisher=SPCR |first=Michael ‘Mike’ |last=Chin |date=2002-03-26 |access-date=10 October 2008 |archive-date=2008-09-18 |archive-url=https://web.archive.org/web/20080918053545/http://www.silentpcreview.com/article6-page1.html |url-status=dead }}</ref> With 3-pin fans, either fixed inline [[resistor]]s or [[diode]]s, or commercial [[fan control]]lers can be used. Software like [[speedfan]] or [[Argus Monitor]] may allow fan speed control. Many newer motherboards support [[pulse-width modulation]] (PWM) control, allowing the fan speed to be set in the [[BIOS]] or with software.
* Mount fans on anti-vibration mounts.
* Remove restrictive fan grills to allow easier airflow, or replace noisy fan grills with quieter versions.
* Use software such as [[Nero AG|Nero]] ''DriveSpeed'' or ''RimhillEx'' to reduce the speed of [[optical drive]]s.
* Isolate hard disk noise, either by using anti-vibration mounts (generally rubber or silicone grommets) or by suspending the hard disk to fully decouple it from the computer chassis by mounting it in a 5.25&nbsp;inch [[drive bay]] with viscoelastic polymer mounts.
* Set the hard disk's [[Automatic Acoustic Management|AAM]] value to its lowest setting. This reduces the seek noise produced by the hard drive but also reduces performance slightly.
* Set operating system to spin down hard drives after a short time of inactivity. This may reduce a drive's life span and commonly conflicts with the OS and running programs, though it can still be useful for drives that are only used for data storage.
* Defragment hard drives to reduce the drive heads' need to search widely for data. This can also improve performance.
* Arrange components and cables to improve airflow. Wires hanging inside the computer can block the airflow, which can increase the temperature. They can be easily moved to the side of the case so that air can pass through more easily.
* Remove dust from inside the computer. Dust on computer parts will retain more heat. Fans draw in dust along with outside air; it can build up quickly inside the computer. Dust can be removed with a vacuum cleaner, [[gas duster]], or compressed air. Special anti-static vacuum cleaners should be used, however, to prevent [[electrostatic discharge]] (ESD). Ideally, this would be done often enough to prevent a significant amount of dust from ever building up. How frequently this would need to be performed would depend entirely on the environment in which the computer is used.

In some cases an acceptable solution may be to relocate the too-noisy computer outside the immediate working area and access it either with long-distance HDMI/USB/DVI cables or via [[remote desktop software]] from a quiet [[thin client]], e.g. based on a [[Raspberry Pi]], a miniature computer that does not even use a heat sink.

==Individual components in a quiet PC==
The following are notes regarding individual components in quiet PCs.

The motherboard, CPU, and video card are major energy users in a computer.  Components that need less power will be easier to cool quietly.  A quiet power supply is selected to be efficient while providing enough power for the computer.

===Motherboard===
{{Main|Motherboard}}
[[Image:Silent PC-Northbridge chipset.JPG|thumb|Passively cooled northbridge chipsets help reduce noise.]]
A motherboard based on a [[chipset]] that uses less energy will be easier to cool quietly. [[Undervolting]] and [[underclocking]] generally require motherboard support, but when available can be used to reduce energy use and heat output, and therefore cooling requirements.

Many modern motherboard chipsets have hot [[Northbridge (computing)|northbridges]] which may come with active cooling in the form of a small, noisy fan. Some motherboard manufacturers have replaced these fans by incorporating large heat sinks or [[heatpipe]] coolers,<ref>{{cite web| url = http://www.madshrimps.be/?action=getarticle&number=1&artpage=1971&articID=473|title=Motherboard Chipset Cooler Roundup |publisher= Mad shrimps | place = [[Belgium|BE]] | first = Mich | last = VM |date= 2006-08-12 | access-date = 2008-10-10}}</ref><ref name= SPCRHeatsinksP2>{{cite web| url = http://www.silentpcreview.com/article30-page2.html |title=Recommended Heatsinks| first = Michael ‘Mike’ | last = Chin| date=2002-07-16| publisher =SPCR|access-date=2008-10-10}}</ref> however they still require good case airflow to remove heat. Motherboard [[voltage regulator]]s also often have heat sinks and may need airflow to ensure adequate cooling.

Some motherboards can control the fan speed using an integrated [[hardware monitoring]] chip<ref name=ieee07/> (often a function within a [[Super I/O]] solution<ref name=ieee07/>), which can be configured through [[BIOS#Hardware monitoring|BIOS]] or with a [[system monitor]]ing software like [[SpeedFan]] and [[Argus Monitor]], and most recent motherboards have built-in PWM fan control for one or two fans.

Even though a given hardware monitoring chip may be capable of performing fan control,<ref name=ieee07>{{Cite conference
|author= Constantine A. Murenin |date= 2007-04-17
|url = http://sensors.cnst.su/IEEE_ICNSC_2007
|section = 2. Hardware review
|title= Generalised Interfacing with Microprocessor System Hardware Monitors
|conference= Proceedings of 2007 IEEE International Conference on Networking, Sensing and Control, 15–17 April 2007.
|location= London, United Kingdom
|publisher=[[IEEE]]
|pages = 901–906 |doi = 10.1109/ICNSC.2007.372901 |isbn = 978-1-4244-1076-7
|id = IEEE ICNSC 2007, pp. 901—906.
}}</ref> a motherboard manufacturer may not necessarily wire up the fan header pins of the motherboard correctly to the hardware monitoring chip, thus sometimes [[computer fan control]] cannot be performed on a given motherboard due to the wiring irregularities, even though the software may indicate that the fan control is available due to the underlying support by the hardware monitoring chip itself.<ref name=abc2010>{{Cite conference
|author1= Constantine A. Murenin
|author2= Raouf Boutaba
|author2-link = Raouf Boutaba
|date= 2010-03-14
|url = http://sensors.cnst.su/fanctl/
|section = 3.1. Shortcomings with general-purpose fan-control software; 7.1. Even easier fan control
|title= Quiet Computing with BSD: Fan control with sysctl hw.sensors.
|conference= AsiaBSDCon 2010 Proceedings. 11–14 March 2010
|location= Tokyo University of Science, Tokyo, Japan
|publication-date= 2010-03-13
|pages=85–92
|archive-url= http://web.archive.org/web/20100225000000/http://sensors.cnst.su/fanctl/
|archive-date= 2010-02-25
|url-status= live
|access-date= 2019-03-10
}} [http://2010.asiabsdcon.org/papers/abc2010-P6B-paper.pdf Alt URL]</ref>  Other times, it may be the case that a single fan-control setting may affect all fan connector headers on the motherboard at the same time, even if individual settings for each fan are available in the hardware monitoring chip itself; these wiring issues being very common makes it difficult to design good general-purpose [[user interface]]s for configuring fan control.<ref name=abc2010/>

Motherboards can also produce [[electromagnetically induced acoustic noise and vibration|audible electromagnetic noise]].

===CPU===
The heat output of a CPU can vary according to its brand and model or, more precisely, its [[thermal design power]] (TDP). [[Intel]]'s third revision [[Pentium&nbsp;4]], using the "Prescott" core, was infamous for being one of the hottest-running CPUs on the market. By comparison, [[AMD]]'s [[Athlon]] series and the Intel [[Core&nbsp;2]] perform better at lower clock speeds and thus produce less heat.

Modern CPUs often incorporate [[Power management|energy saving systems]], such as [[Cool'n'Quiet]], [[LongHaul]], and [[SpeedStep]]. These reduce the CPU [[clock speed]] and [[core voltage]] when the processor is idle, thus reducing heat.  The heat produced by CPUs can be further reduced by [[undervolting]], [[underclocking]] or both.

Most modern mainstream and value CPUs are made with a lower [[Thermal Design Power|TDP]] to reduce heat, noise, and power consumption. Intel's dual-core [[Celeron]], [[Pentium]], and i3 CPUs generally have a [[Thermal design power|TDP]] of 35&ndash;54&nbsp;W, while the i5 and i7 are generally 64&ndash;84&nbsp;W (newer versions, such as [[Haswell (microarchitecture)|Haswell]]) or 95W (older versions, such as [[Sandy Bridge]]). Older CPUs such as the [[Core 2 Duo]] typically had a TDP of 65&nbsp;W, while the [[Core 2 Quad]] CPUs were mostly 65&ndash;95&nbsp;W. AMD's [[Athlon II x2]] CPUs were 65&nbsp;W, while the Athlon&nbsp;x4 was 95&nbsp;W. The [[AMD Phenom]] ranged from 80&nbsp;W in the x2 variant to 95 and 125&nbsp;W in the quad-core variants. The [[AMD Bulldozer]] CPUs range from 95&ndash;125&nbsp;W. [[AMD APU]]s range from 65&nbsp;W for the lower-end dual-core variants, such as the A4, to 100&nbsp;W in the higher-end quad-core variants, such as the A8. Some processors come in special low-power versions. For example, Intel's lower TDP CPUs end in T (35&nbsp;W) or S (65&nbsp;W).

===Video card===
[[File:Sapphire-Radeon-HD-7750.jpg|thumb|A video card using [[heat pipe]]s for cooling and no dedicated fan]]
[[Video cards]] can produce a significant amount of heat. A fast [[GPU]] may be the largest power consumer in a computer<ref>{{cite web |url=http://www.xbitlabs.com/articles/video/display/radeon-hd-2900-games.html |title=Almost a Champion: ATI Radeon HD 2900 XT Gaming Performance Review |first1=Alexey |last1=Stepin |first2=Yaroslav |last2=Lyssenko |first3=Anton |last3=Shilov |date=2007-05-24 |publisher=X bit labs |access-date=10 October 2008}}</ref> and because of space limitations, video card coolers often use small fans running at high speeds, making them noisy.

Options to reduce noise from this source include:
* Replace the stock [[computer cooling|cooler]] with an aftermarket one.<ref>{{Citation |url=http://hexus.net/tech/news/cooling/43577-new-arctic-accelero-hybrid-7970-graphics-card-cooler/ |title =New Arctic Accelero Hybrid 7970 graphics card cooler |publisher=Hexus |date=2012-10-08 |access-date=2012-09-18}}.</ref>
* Use motherboard video output. Typically, motherboard video takes less power but provides lower gaming or HD video decoding performance.
* Select a video card that does not use a fan.<ref>{{cite web |url=http://www.silentpcreview.com/forums/viewtopic.php?t=14366 |title=Fanless VGA Cards list – a start! |first=Michael ‘Mike’ |last=Chin |date=2004-07-16 |publisher=SPCR |type=forum |access-date=2008-10-10}}</ref>
* Most modern graphics cards come with tools that allow the user to reduce the power target and adjust fan curves, resulting in quieter operation at the cost of performance

===Power supply===
{{Main|Power supply unit (computer)}}
[[Power supply]] (PSU) is made quieter through the use of higher efficiency (which reduces waste heat and need for airflow), quieter fans, more intelligent fan controllers (ones for which the correlation between temperature and fan speed is more complex than linear), more effective heat sinks, and designs that allow air to flow through with less resistance. For a given power supply size, more efficient supplies such as those certified [[80 plus]] generate less heat.

A power supply of appropriate wattage for the computer is important for high efficiency and minimizing heat. Power supplies are typically less efficient when lightly or heavily loaded. High-wattage power supplies will typically be less efficient when lightly loaded, for instance when the computer is idle or sleeping. Most desktop computers spend most of their time lightly loaded.<ref name=SPCRPower>{{cite web| url = http://www.silentpcreview.com/article699-page1.html | title=Recommended Power Supplies| first= Michael ‘Mike’ | last = Chin| date=2006-12-01 |publisher=SPCR |access-date=2008-10-10}}</ref> For example, most desktop PCs draw less than 250 watts at full load, and 200 watts or less is more typical.<ref>{{cite web| url = http://www.silentpcreview.com/article28-page4.html |title= Power Supply Fundamentals| first = Michael ‘Mike’ | last = Chin|date=2005-04-06 |publisher=SPCR |access-date= 2008-10-10}}</ref>

Power supplies with thermally controlled fans can be made quieter by providing a cooler and/or less obstructed source of air, and fanless power supplies are available, either with large passive heat sinks or relying on convection or case airflow to dissipate heat. It is also possible to use fanless DC-to-DC power supplies that operate like those in laptops, using an external power brick to supply DC power, which is then converted to appropriate voltages and regulated for use by the computer.<ref>{{cite web| url=http://www.silentpcreview.com/article601-page1.html|title=Tiny, Silent and Efficient: The picoPSU | first = Michael ‘Mike’ | last = Chin| date=2006-05-09 |publisher=SPCR |access-date= 2023-07-31 | archive-date= 2016-11-19 | archive-url = https://web.archive.org/web/20161119011614/http://www.silentpcreview.com/article601-page1.html | url-status = dead}}</ref> These power supplies usually have lower wattage ratings.

The electrical coils in power supplies can produce [[Electromagnetically induced acoustic noise and vibration|audible electromagnetic noise]] which can become noticeable in a quiet PC.

Equipping the PSU with a power cord that uses a ferrite bead can sometimes help to reduce humming from the PSU.

===Case===
{{Main|Computer case}}
[[Image:Silent PC-Antec P180.JPG|thumb|Antec P180, with isolated chambers for more segregated airflow]]
[[Image:Antecp180b.JPG|thumb|Another example of the Antec P180, this one demonstrating the use of the Scythe Ninja, a fanless CPU cooler]]
Case designed for low noise usually include quiet fans, and often come with a quiet power supply. Some incorporate heatsinks to cool components passively.<ref>{{cite web | url = http://www.silentpcreview.com/article301-page1.html|title=Fanless Ultra Powerhouse PC by EndPCNoise | first = Michael ‘Mike’ | last = Chin |publisher=SPCR |date=2006-02-23| access-date=2008-10-10}}</ref>

Larger cases provide more space for airflow, larger coolers and heat sinks, and sound-dampening material.

====Airflow====
Noise-optimized cases<ref>{{Citation | url = http://www.silentpcreview.com/article255-page1.html | title = Antec P180 | date = 21 April 2020 | publisher = SPCR}}.</ref><ref>{{Citation | url = http://www.silentpcreview.com/article272-page1.html | title = Antec P150 | date = 21 April 2020 | publisher = SPCR}}.</ref> often have ducting and partitioning within the case to optimize airflow and to thermally isolate components.<ref>{{cite web| url=http://www.silentpcreview.com/article75-page4.html|title = Cases: Basics & Recommendations| first = Michael ‘Mike’ | last = Chin|date=2003-03-12 |publisher= SPCR | access-date = 2008-10-10}}</ref> Vents and ducts may easily be added to regular cases.<ref>{{cite web| url = http://www.silentpcreview.com/article293-page2.html | title= Quiet PC for Torrid Thailand| first = Michael ‘Mike’ | last = Chin|date=2006-01-10 |publisher=SPCR |access-date= 2008-10-10}}</ref>

Case designed to be quiet typically have wire grills or honeycombed fan grills. Both are far superior to the older style of stamped grill.

Features that facilitate neat cable management, such as brackets and space to run cables behind the motherboard tray, help increase cooling efficiency.

Air filters can help to prevent dust from coating heat sinks and surfaces, which dust impedes heat transfer, making fans spin faster. However, the filter itself can increase noise if it restricts airflow too much or is not kept clean, requiring a larger or faster fan to handle the pressure drop behind the filter.

====Soundproofing====
The inside of a case can be lined with [[Soundproofing|dampening materials]] to reduce noise by:
* attenuating the vibration of the case panels via extensional damping or constrained-layer damping
* reducing the amplitude of the vibration of the case panels by increasing their mass
* absorbing airborne noise, such as with foam

===Cooling systems===
{{Main|Computer cooling}}

====Heat sink====
{{Main|Heat sink}}
Large heat sinks designed to operate efficiently with little airflow are often used in quiet computers.<ref name=MadsHeatsinks>{{cite web | place = [[Belgium|BE]] | url = http://www.madshrimps.be/?action=getarticle&articID=389 |title = All Heatsink Tests Done by Madshrimps In One Place (CPU Heatsink Comparison Database) |author=jmke |date=2009-12-07 |publisher=Madshrimps |access-date = 2013-11-21}}</ref><ref>{{cite web| url=http://www.silentpcreview.com/article251-page1.html|title = Scythe SCNJ-1000 Ninja heatsink| first = Michael ‘Mike’ | last = Chin|date=2005-06-17 |publisher=SPCR | access-date = 2013-11-21}}</ref><ref name=SPCRHeatsinks>{{cite web| url= http://www.silentpcreview.com/article30-page1.html | title = Recommended Heatsinks| first = Michael ‘Mike’ | last = Chin|date= 2002-07-16 | publisher= SPCR | access-date = 2008-10-10}}</ref> Often [[heat pipes]] are used to more efficiently distribute heat to the heat sink.

====Fan====
{{Main|Computer fan}}
[[Image:Silent PC-large fan.JPG|thumb|A 120 mm variable speed fan]]

If they use fans at all, quiet PCs typically use larger-than-usual low-speed fans with quiet-running motors and bearings. The 120&nbsp;mm size is common, and 140&nbsp;mm fans are used where cases or heat sinks allow them. Quiet fan manufacturers include Nexus, EBM-Papst,<ref>{{Citation | url = http://www.ebmpapst.com/ | title = EBM Papst}}.</ref> Yate Loon, Scythe,<ref>{{Citation | url = http://www.scythe-eu.com/en | title = Scythe | place = [[EU]]}}</ref> and [[Noctua (cooling)|Noctua]].<ref>{{cite web | newspaper = Digital daily | url= http://www.digital-daily.com/cooling/noctua/index2.htm | title = New coolers Noctua NH-U9 and NH-U12 – quiet and effective cooling | access-date =2008-10-10 | first =Viktor | last = Baranov|date=2006-05-23}}</ref> Extensive comparative surveys have been posted by SPCR<ref>{{cite web| url=http://www.silentpcreview.com/article695-page1.html | publisher =SPCR | title = Fan Round-Up | number = 2 | access-date =2008-10-10 | first = Michael ‘Mike’ | last = Chin| date=2006-11-27}}</ref><ref>{{cite web| url = http://www.silentpcreview.com/article63-page2.html | title = Recommended Fans| first = Michael ‘Mike’ | last = Chin | date=2007-03-04 |publisher=SPCR | access-date=2008-10-10}}</ref> and MadShrimps.<ref>{{cite web| url = http://www.madshrimps.be/?action=getarticle&articID=421 |title=120mm Fan Roundup: 17 Fans Compared |publisher= Madshrimps | place = [[Belgium|BE]] | date=2002-07-16|access-date=2008-10-10}}</ref><ref>{{cite web| url= http://www.madshrimps.be/gotoartik.php?articID=892 |title=120mm Fan Roundup: 35 Fans Compared | date=2008-02-13 | publisher = Mad shrimps | place = BE |access-date= 2009-02-13}}</ref>

Fan noise is often proportional to fan speed, so [[fan control]]lers can be used to slow down fans and to precisely choose fan speed. Fan controllers can produce a fixed fan speed using an inline resistor or diode; or a variable speed using a [[potentiometer]] to supply a lower voltage. Fan speed can also be reduced more crudely by plugging them into the power supply's 5-volt line instead of the 12-volt line (or between the two for a potential difference of 7 volts, although this cripples the fan's speed sensing).<ref name=7vTrick /> Most fans will run at 5 volts once they are spinning, but may not start reliably at less than 7 V. Some simple fan controllers will only vary the fans' supply voltage between 8 V and 12 V to avoid this problem entirely. Some fan controllers start the fan at 12 V, then drop the voltage after a few seconds.

PWM fan control, however, is the easiest and most efficient option for modern motherboards that have PWM fan headers. [[PWM fan]] control rapidly cycles between feeding the fan full voltage and no voltage, to control rotational speed. Typically the motherboard chipset provides temperature data from sensors on the CPU itself to control speed.

Bearing and motor noise is an important consideration. Soft mounting fans (e.g. with rubber or silicone fan isolators) can help reduce transfer of fan vibration to other components.<ref>{{cite web| url= http://www.silentpcreview.com/article262-page1.html| title = AcoustiProducts Vibration Dampers| first = Michael ‘Mike’ | last = Chin|date=2005-08-11 |publisher=SPCR | access-date = 2008-10-10}}</ref>

Piezoelectric fans are often quieter than rotating fans and may consume less power.<ref>{{cite web| url= http://electronics-cooling.com/articles/2007/feb/a1/ | title =Piezo actuators for electronics cooling | first =Ioan | last = Sauciuc |publisher=Electronics Cooling Magazine |date=February 2007 |access-date= 2008-10-10}}</ref><ref>{{cite web|last1=braun|first1=Rob|title=Compact Mac Upgrades|url=https://mac68k.info/wiki/display/mac68k/Compact+Mac+Upgrades|publisher=mac68k.info|access-date=3 April 2016}}</ref> Intel, Murata, and others have recently done development on use of piezoelectric fans in desktop PCs.<ref>{{Cite report |doi=10.21236/ada288571 |title=Ada Compiler Validation Summary Report: Certificate Number 940902S1.11377 UNISYS Corporation. IntegrAda for Windows NT, Version 1.0. Intel Deskside Server with Intel 80486DX266 =&gt; Intel Deskside Server with Intel 80486DX266, |last=Jefferson |first=David K. |last2=Johnson |first2=L. A. |last3=Peifer |first3=Donald J. |date=1994-09-14 |publisher=Defense Technical Information Center |location=Fort Belvoir, VA}}</ref>

====Watercooling====
{{Main|Watercooling#Computer usage}}
Watercooling<ref>{{cite web|last1=Acosta|first1=Jeremy|title=Water Cooling or Air Cooling For PC|url=http://gamesngearselite.com/air-cooling-vs-liquid-cooling/|website=Games and Gears Elite|access-date=2017-02-14|archive-date=2017-02-11|archive-url=https://web.archive.org/web/20170211091531/http://gamesngearselite.com/air-cooling-vs-liquid-cooling/|url-status=dead}}</ref> is a method of heat-dissipation by transferring the heat through a conductive material which is in contact with a liquid, such as demineralized water with an additive to prevent bacterial growth. This water travels in a loop that usually contains a reservoir, radiator and pump. Modern 12 V DC pump technologies allow extremely powerful and quiet designs.

By efficiently transferring device heat to a separate heat exchanger that can use larger heat sinks or fans, water cooling can allow quieter overall operation. Devices such as [[GPU]]s, [[Northbridge (computing)|Northbridges]], [[Southbridge (computing)|Southbridges]], [[hard disk drive]]s, [[Random access memory|memory]], [[voltage regulator module]]s (VRMs), and even [[Power supply unit (computer)|power supplies]] can be separately watercooled;<ref>{{Cite web|url=http://koolance.com/1300-1700w-liquid-cooled-power-supply|title=Koolance 1300/1700W Liquid-Cooled Power Supply}}</ref> in fact [[Server immersion cooling|the whole PC]] can be immersed, in some cases.

===Secondary storage===

====Hard drive====
{{Main|Hard drive}}
[[Image:Silent PC-silicone grommets.JPG|thumb|Silicone grommets in a computer case for mounting a hard drive to reduce vibration]]
Older hard drives used [[ball bearing]] motors but more recent desktop hard drives use quieter [[fluid bearing]] motors.<ref name=SPCRrecomendHD>{{cite web| url=http://www.silentpcreview.com/article29-page2.html| title = Recommended Hard Drives| publisher=SPCR | first = Michael ‘Mike’ | last = Chin|date=2002-09-18| access-date = 2008-08-02}}</ref>

The smaller 2.5" form-factor hard drives generally vibrate less, are quieter, and use less power than traditional 3.5" drives,<ref name= SPCRrecomendHD /><ref>{{cite web| url = http://www.silentpcreview.com/article264-page3.html | title = Seagate Momentus 5400.2 120GB SATA notebook drive| first = Michael ‘Mike’ | last = Chin| date= 2005-08-16 |publisher= SPCR | access-date= 2008-10-10}}</ref> but often have lower performance and less capacity, and cost more per [[gigabyte]].

To minimize vibrations from a hard drive being transferred to, and amplified by the case. Hard drives can be mounted with soft rubber studs, suspended with elastics, or placed on soft foam or [[Sorbothane]].  Hard disk enclosures can also help reduce drive noise, but care must be taken to ensure that the drive gets adequate cooling - with disk temperatures often monitored by [[Self-Monitoring, Analysis, and Reporting Technology|SMART]] software.

====Solid-state storage====
{{main|Solid-state drive}}
A [[solid-state drive]] has no moving mechanical components and runs silently,<ref name="STEC">[[STEC, Inc.|STEC]]."[http://www.stec-inc.com/downloads/whitepapers/Performance_Power_Advantages.pdf SSD Power Savings Render Significant Reduction to TCO] {{webarchive|url=https://web.archive.org/web/20100704203915/http://www.stec-inc.com/downloads/whitepapers/Performance_Power_Advantages.pdf |date=2010-07-04 }}." Retrieved October 25, 2010.</ref><ref>{{cite web |last=Whittaker|first=Zack|title=Solid-state disk prices falling, still more costly than hard disks |url=https://www.zdnet.com/article/solid-state-disk-prices-falling-still-more-costly-than-hard-disks/|work=Between the Lines|publisher=ZDNet|access-date=14 December 2012}}</ref><ref>{{cite web |title=What is solid state disk? - A Word Definition From the Webopedia Computer Dictionary|url=http://www.webopedia.com/TERM/S/solid_state_disk.html|work=Webopedia|date=7 January 2001|publisher=ITBusinessEdge|access-date=14 December 2012}}</ref><ref name="dell-study">{{cite web|url=http://www.dell.com/downloads/global/products/pvaul/en/ssd_vs_hdd_price_and_performance_study.pdf|title=SSD vs HDD Price and Performance Study, a Dell technical white paper|date=May 2011|publisher=Dell PowerVault Technical Marketing|author=Vamsee Kasavajhala|access-date=15 June 2012}}</ref> but ({{As of|2016|lc=yes}}) are still roughly four times more expensive per unit of storage than consumer-grade HDDs.<ref>{{cite web |url=http://www.computerworld.com/article/3040694/data-storage/ssd-prices-plummet-again-close-in-on-hdds.html|title=SSD prices plummet again, close in on HDDs|author=Lucas Mearian|date=3 March 2016|work=Computerworld}}</ref>

In some cases, other solid-state storage methods may be suitable:
* [[Compact Flash]] (CF) cards can be used as secondary storage. Because they use a slightly modified [[Parallel ATA]] (PATA) interface, a simple adapter is all that is needed to connect CF cards to function as an PATA or [[PC Card]] hard disk.  CF cards are also small, allowing [[Small form factor (desktop and motherboard)|SFF]] PCs to be made, produce no noise, use very little power (further reducing heat output in the AC/DC conversion in the PSU), and an insignificant amount of heat. However, they are very expensive per [[Gigabyte|GB]] and are only available in small capacities and there are also issues regarding the maximum number of writes to each sector.<ref>{{cite web| url=http://blogs.msdn.com/embedded/archive/2005/10/26/485389.aspx|title=Where to find EWF Information|publisher=msdn.com | date=2005-10-26|access-date=2008-10-10}}</ref>
* [[USB flash drives]] can be used if a motherboard supports booting from [[USB]]. They are based on [[flash memory]], so have the same advantages and disadvantages as CF cards, except that speed is limited by the [[USB#Limitations|USB bus]].
* [[i-RAM]] is a solid-state disk that has four DIMM slots to allow regular PC [[RAM]] to be used like a disk. It is much faster than a hard disk, does not have the write cycle limitations of flash memory, however, it requires power continuously in order to maintain its contents (from standby power or a battery when the system is off), uses more power than many laptop hard drives, has maximum capacity of 4 GiB, and is expensive.

All forms of solid-state storage are more expensive than traditional spinning-disk drives, so some quiet PC designs use them in conjunction with a secondary hard drive which is only accessed when needed, or with [[network-attached storage]], where less-quiet traditional hard drives are kept remote.

====Optical drive====
Optical drives can be slowed down by software to quiet them, such as [[Nero Burning ROM|Nero]] DriveSpeed, or emulated by [[Disk image emulator|virtual drive programs]] such as [[Daemon Tools]] to eliminate their noise entirely. Notebook optical drives can be used, which tend to be quieter, however, this may be because they tend to run slower (typically 24× CD speed, 8× DVD speed).  Some DVD drives have a feature, commonly called [[Riplock]], which reduces drive noise by slowing the drive during video playback.  For playback operations, only 1x (real time) speed is required.

===External components===

====Monitor====
{{Main|Computer display}}
A [[CRT monitor]] can produce [[coil noise]], as can the external power supply for an [[LCD]] monitor or the voltage converter for the monitor's backlight.  LCD monitors tend to produce the least noise (whine) when at full brightness.<ref name= SPCRLCDwhine/>  Reducing brightness using the video card does not introduce whine but may reduce color accuracy.<ref name=SPCRLCDwhine />  An LCD monitor with an external power supply tucked out of the way will produce less noticeable noise than one with the power supply built into the screen housing.

====Printer====
{{Main|Computer printer}}
In the past, particularly noisy printers such as [[Dot matrix printer|dot matrix]] and [[daisy wheel]] designs were often housed in soundproofed boxes or cabinets, and the same technique can be used with modern printers to reduce their perceived noise. Another solution is to network the printer and locate it physically away from the immediate work area.

==Laptop==
{{Main|Laptop}}
In contrast to desktop PCs, laptops and notebooks typically do not have power supply fans or video card fans and generally use physically smaller hard drives and lower-power components. However, laptop CPU fans are usually smaller, so may not necessarily be quieter than their desktop counterparts - a smaller fan area requires faster fan speeds to move the same amount of air.<ref>{{Cite web|title=Fluid Volumetric Flow Rate Equation - Engineers Edge|url=https://www.engineersedge.com/fluid_flow/volumeetric_flow_rate.htm|access-date=2020-08-14|website=www.engineersedge.com}}</ref> Furthermore, limited space, limited access and proprietary components make silencing them more difficult.

===Fanless===
A number of laptops and netbooks however do not use cooling fans at all.<ref>{{cite web| url=http://reviews.cnet.com/laptops/dell-latitude-x1/4505-3121_7-31320873.html|title=Dell Latitude X1 Laptop Reviews | first =Brian | last = Nadel|date=2005-04-28|publisher=CNET |access-date=2008-10-10}}</ref><ref>{{cite web|url=http://www.toughbook.eu/media/SpecSheet_CF-W5_en.pdf |title=Panasonic CF-W5 Specification Sheet |publisher=Toughbook |place=[[EU]] |access-date=2008-10-10 |url-status=dead |archive-url=https://web.archive.org/web/20070224022027/http://www.toughbook.eu/media/SpecSheet_CF-W5_en.pdf |archive-date=February 24, 2007 }}</ref><ref>{{cite web|url=http://www.toughbook.eu/media/SpecSheet_CF-T5_en.pdf |title=Panasonic CF-T5 Specification Sheet |publisher=Toughbook |place=EU |access-date=2008-10-10 |url-status=dead |archive-url=https://web.archive.org/web/20070216154520/http://www.toughbook.eu/media/SpecSheet_CF-T5_en.pdf |archive-date=February 16, 2007 }}</ref><ref>{{cite web| url= http://www.notebookreview.com/default.asp?newsID=2695| title = Fujitsu P7120 (P7120D) | first =Brian | last = Beeler|date= 2006-01-03| publisher= [[Notebook Review]] | access-date = 2008-10-10}}</ref>{{Update inline|date=February 2021|reason=These sources are all over 20 years old (see [[Wikipedia:Reference desk/Archives/Computing/2021 February 17#Modern Quiet PCs]])}}

Fanless [[portable computer]]s ([[tablet pc]]s, [[subnotebook]]s, [[chromebook]]s,  [[ultrabook]]s and [[2-in-1 PC]]s) running under 10-15&nbsp;W<ref>{{cite web |url=https://www.electronicsweekly.com/news/fanless-computer-boards-are-pushing-15w-to-the-limit-2015-10/ |title=Fanless computer boards are pushing 15W to the limit |author=Richard Wilson |date=15 October 2015 |access-date=2021-10-18}}</ref> on [[mobile CPU]]s (most commonly [[ARM processor]]s) became popular after [[netbook]]s but then mainly after the introduction of the first [[iPad]] in 2010. The first iPad's CPU, the [[ARM Cortex-A8]] was the first Cortex design to be adopted on a large scale in consumer devices.<ref name="themobileindian gupta 2013-04-26">{{cite news | url=http://www.themobileindian.com/news/11825_ARM-Cortex:-The-force-that-drives-mobile-devices | title=ARM Cortex: The force that drives mobile devices | work=The Mobile Indian | date=April 26, 2013 | access-date=2013-05-15 | author=Gupta, Rahul}}</ref>

==See also==
* [[Keyboard computer]]

==References==
{{Reflist}}

==External links==
{{wikibooks|How To Assemble A Desktop PC|Silencing}}
* {{Citation | url = http://www.silentpcreview.com/ | title = Silent PC Review}} – articles on various aspects of PC acoustics.
** {{Citation | url = http://www.silentpcreview.com/article669-page1.html | title = What is a "Silent" Computer? | date = 21 September 2006 | publisher = Silent PC Review}}.
** {{Citation | publisher = Vrad | url = http://www.vrad.info/ | title = What is a "Silent" Computer? | language = nl}}.
** {{Citation | publisher = Silent PC Review | url = http://www.silentpcreview.com/section5.html | title = Reference/Recommended}}.
** {{Citation | publisher = Silent PC Review | url = http://www.silentpcreview.com/forums/viewtopic.php?t=21152 | title = In a nutshell}}.
* {{Citation | url = http://silent.se/pc | publisher = Silent | title = PC | place = [[Sweden|SE]]}}.

{{Home theater PC (application software)}}

{{DEFAULTSORT:Quiet Pc}}
[[Category:Personal computers]]
[[Category:Computers and the environment]]
[[Category:Noise pollution]]