Are laptops supposed to be quiet?

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.

MotherboardEdit

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 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,[12][13] however they still require good case airflow to remove heat. Motherboard voltage regulators 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[14] [often a function within a Super I/O solution[14]], which can be configured through BIOS or with a system monitoring 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,[14] 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.[15] 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 interfaces for configuring fan control.[15]

Motherboards can also produce audible electromagnetic noise.

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 Pentium4, 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 Core2 perform better at lower clock speeds, and thus produce less heat.

Modern CPUs often incorporate 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 TDP to reduce heat, noise, and power consumption. Intel's dual-core Celeron, Pentium, and i3 CPUs generally have a TDP of 3554W, while the i5 and i7 are generally 6484W [newer versions, such as Haswell] or 95W [older versions, such as Sandy Bridge]. Older CPUs such as the Core 2 Duo typically had a TDP of 65W, while the Core 2 Quad CPUs were mostly 6595W. AMD's Athlon II x2 CPUs were 65W, while the Athlonx4 was 95W. The AMD Phenom ranged from 80W in the x2 variant to 95 and 125W in the quad-core variants. The AMD Bulldozer CPUs range from 95125W. The APUs range from 65W for the lower-end dual-core variants, such as the A4, to 100W 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 [35W] or S [65W].

Video cardEdit

Video card can produce a significant amount of heat. A fast GPU may be the largest power consumer in a computer[16] 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 cooler with an aftermarket one.[17]
• 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.[18]
• 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 a cost of performance

Power supplyEdit

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.[19] For example, most desktop PCs draw less than 250 watts at full load, and 200 watts or less is more typical.[20]

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.[21] These power supplies usually have lower wattage ratings.

The electrical coils in power supplies can produce 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 designed for low noise usually include quiet fans, and often come with a quiet power supply. Some incorporate heatsinks to cool components passively.[22]

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

AirflowEdit

Noise-optimized cases[23][24] often have ducting and partitioning within the case to optimize airflow and to thermally isolate components.[25] Vents and ducts may easily be added to regular cases.[26]

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.

SoundproofingEdit

The inside of a case can be lined with 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 systemsEdit

Heat sinkEdit

Large heat sink designed to operate efficiently with little airflow are often used in quiet computers.[27][28][29] Often heat pipes are used to more efficiently distribute heat to the heat sink.

FanEdit

If they use fans at all, quiet PCs typically use larger-than-usual low-speed fans with quiet-running motors and bearings. The 120mm size is common, and 140mm fans are used where cases or heat sinks allow them. Quiet fan manufacturers include Nexus, EBM-Papst,[30] Yate Loon, Scythe,[31] and Noctua.[32] Extensive comparative surveys have been posted by SPCR[33][34] and MadShrimps.[35][36]

Fan noise is often proportional to fan speed, so fan controllers 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].[11] 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.[37]

Piezoelectric fans are often quieter than rotating fans and may consume less power.[38][39] Intel, Murata, and others have recently done development on use of piezoelectric fans in desktop PCs.[citation needed]

WatercoolingEdit

Watercooling[40] is a method of heat-dissipation by transferring the heat through a conductive material which is in contact with a liquid, such as demineralised 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, watercooling can allow quieter overall operation. Devices such as GPUs, Northbridges, Southbridges, hard disk drives, memory, voltage regulator modules [VRMs], and even power supplies can be separately watercooled;[41] in fact the whole PC can be immersed, in some cases.

Secondary storageEdit

Hard driveEdit

Older hard drive used ball bearing motors but more recent desktop hard drives use quieter fluid bearing motors.[42]

The smaller 2.5" form-factor hard drives generally vibrate less, are quieter, and use less power than traditional 3.5" drives,[42][43] 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 be monitored by SMART software.

Solid-state storageEdit

A solid-state drive has no moving mechanical components and runs silently,[44][45][46][47] but [as of 2016] are still roughly four times more expensive per unit of storage than consumer-grade HDDs.[48]

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 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 GB and are only available in small capacities and there are also issues regarding the maximum number of writes to each sector.[49]
• 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 bus.
• i-RAM is a solid-state disk which 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 driveEdit

Optical drives can be slowed down by software to quiet them, such as Nero DriveSpeed, or emulated by 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 [or real time] speed is required.

External componentsEdit

MonitorEdit

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.[7] Reducing brightness using the video card does not introduce whine, but may reduce color accuracy.[7] 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.

PrinterEdit

In the past, particularly noisy printers such as 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.