Products available to control PC noise

Cases: There are some cases designed to be quiet and marketed on that claim. Using a search engine for terms like “quiet cases” or “totally no noise cases” should point you in the right direction. Some of these cases are built like huge heat-sinks and use clever technology that will allow you to dispense with the use of all fans inside the PC, including processor, graphics card and other fans. There are other cheaper cases marketed as quiet cases that have an acoustic lining inside the case that absorbs some of the internal sounds. Either way having a quality case makes a lot of difference. Case rattle is one of the most common causes of PC noise (see section 1 above on “cheapest ways to reduce noise”)

Acoustic lining: A variety of acoustic lining products are available. Some of them are basic sheets of foam. Some are dual layer products with a thicker barrier material under a layer of sound absorbing foam. These lining products usually have self adhesive  backing. You can cut the sheets to fit along the inside of your case, peel the back off and fit them yourself. Some acoustic lining products are as little as 3-4 mm in thickness, others as much as 17 mm. If space is restricted in your case you may want to go for the thinner (but less effective) products. Things to note: There are some cheap bitumen based products that degrade quickly over time and can be quite risky. Also, if your PC does rely extensively on the case body to dissipate heat (as is common with many aluminium cases) then you may want to create some additional airflow to compensate for the reduced cooling. You can do this via extra chassis fans. The blocks of foam in the picture fit into empty 5.25" and 3.5" drive bays to fill space that may otherwise be trapping hot air. Using these foam blocks reduces the volume of air within the box resulting in a faster "turnover" of air. 

CPU (Processor) fans: A variety of specialist fan manufacturers make low noise heat sink + fans combinations for processors. These involve using copper contacts to better transfer heat from the processor to the heat sink, using large heat sinks to quickly move the heat away from the CPU, and using large, low noise fans to blow air over the heat sink. Under 30 dba is usually considered quiet for these fans. The problem with larger heat sinks is that they don’t fit in all cases and they are particularly not suited to low profile desktop cases so please do check the available space above your processor before you buy one of these.

Water cooling: This has been gaining popularity despite the obvious downsides of combining water and electricity. As liquid absorbs and transfers heat more effectively than air does there is a practical argument in favour of water cooling. How it works is that the specially manufactured processor heat sink has two tubes connected to it. One feeds liquid to the heat sink and the other takes the liquid back to the external pump. Some cases manufacturers now provide the water cooling kits as options with some of their cases. One or two manufacturers also provide the water cooling kits integrated into some of their larger cases saving you the unsightly mess of having a pump and tubes on your table top. In either case though you will need to have an external "radiator" unit that dispels the heat.

The problem with water of course, is that unlike air cooled systems water needs to be enclosed. And it needs to stay enclosed – with no leaks - or it will damage the electronic components in your PC. This makes for equipment that is both bulky and expensive.

Other Cooling: Peltier coolers and other heat exchange systems have been tried in PCs with limited success. Issues like condensation etc cause problems in peltier solutions. Also, peltier coolers need your heat to be constant. If your PC isn't under constant, even use and/or you have energy saving features that trigger "sleep/suspension" modes or "CPU idling" you can't use a Peltier refrigerator/cooler; that excludes most PCs. Thermoelectric engineers have experimented with turning heat into electricity in a variety of other ways but most methods require large amounts of heat - about 200-300 degrees C - and even then only about 20% of the heat is converted to electricity. Other thermoelectric solutions consume a lot of power and/or generate substantial heat themselves and require active cooling. 

Hard Disks: Apart from the fans in a PC hard disks are the only moving parts that are always moving (optical drives only move when you have a DVD or CD in them). In 2022 it’s possible to buy/build a PC without fans but you still can’t have one without a hard disk (unless it’s a thin client on a network – but that’s another story). And hard disks are usually noisy. Your data is stored on platters on the disk and there are reading heads in the drive that write this data to the platters and access/read the data when you need it. The spinning of the drive causes the whining noise you get with hard disk. The head moving about causes the trashing sound. Hard disks started off at relatively low speeds. The fastest hard disks were SCSI disks at 7200 rpm spindle speeds but these were used only in server environments. However, 7200 rpm reached the desktop PC a few years ago and newer desktop hard disks even run at 10,000 rpm. That’s a lot of revolutions per minute. Fortunately, these advances in hard disk speeds have been accompanied by new technologies to limit the noise the disk generates. Most hard disk manufacturers now either offer a range of quiet disks or use special quietening techniques on all their disks. If you’ve got an existing older hard disk that you need to control the sound on - or even a newer disk that’s just too noisy for you - here are some products that may help.

Hard disk mounts: These are L shaped metal blocks with rubber in between. Hard disks typically have four contact points with the case i.e. at the four holding screws. If you have a spare 5.25” bay however you can use these mounts and move the hard disk to the larger bay. At each corner of the disk you’ll have one L shaped mount screwed on to the hard disk and one on to the bay ensuring that the metal from the hard disk doesn’t touch the metal on the bay and therefore reduces vibrations transferred to the case.

Hard disk heat sinks, like in the picture here, serve two purposes. They have four rubber rings that act like the mounts above which prevent the hard disk coming into direct contact with the case. They do also have a heat sink consisting of a collection of copper pipes that dissipates heat from the higher spindle speeds drives.

Enclosures: Some manufacturers sell complete enclosures for your hard disk. An enclosure will typically fit in a 5.25” bay and completely contain your hard disk i.e. a little box into which your hard disk vibration and noise disappears ... theoretically. Please do be very, very careful with these enclosures though. Check that they are rated to handle the spin speed of your hard disk and are capable of getting rid of the heat the hard disk generates. Some enclosures dissipate the heat via one or two little fans. And, as with any fans, these will generate some noise themselves so you’ll have to balance that against the saving of hard disk sounds.

Recently there have been major advantages in storage technologies. Flash memory cards have been getting bigger and bigger. Soon there will be storage devices like flash memory cards that will hold an entire operating system and your other files thus dispensing with the moving hard disk altogether. In fact such devices do exist right now but they are so horrendously expensive that they are used only in very select situations like space exploration and military applications. (At the last check a half decent size “disk” was $40,000).

Power Supplies: In many PCs this is the component that generates the most noise. When choosing a PSU for your PC shopping around can save you a lot of sound. Manufacturers of quality PSUs normally have a noise rating listed along with the technical specs. Further, using the right wattage of PSU for your PC does help, if you don’t need a 550 watt power supply, why buy one. It will probably make the same amount of noise even if you are only demanding 200 watts of power out of it. If the budget stretches to it there are some PSUs now available that are completely fan-less. These tend to come as standard on very expensive cases that are marketed as quiet cases, but some of them are also available for purchase to fit in any standard PC. They dissipate heat via a large radiator type heat sink that sits outside the PSU and outside the PC. Some of the heat sinks stick out a few inches behind the computer.

Graphics card “VGA heat pipes”:  Performance graphics/video cards do of course generate a lot of heat. In fact the processors on today’s high end graphics cards have more power than the main CPU in any PC you’ve had for a few years. Because of the international standardisation on size and location of PCI and AGP cards the graphics card fan has to be fairly small. This of course means that it needs to spin faster to keep the card cool. Some cards have high performance RAM on their flip side and sometimes these need active cooling too. The best route to take with graphics cards is - as with the PSUs described above – if you don’t need the power then settle for a lower tech option. But if you’d still like to lower/remove the sound from the graphics card’s fan you’ll have to shop around for a VGA heat pipe like the one in the picture below. To fit it you’ll have to remove the heat sink and fan your graphics card came with (and lose the manufacturer’s warranty on the card for “tampering” with it) and fit a VGA heat sink instead. This spreads the heat over a much wider surface area and provided you have sufficient airflow over the VGA heat sink/heat pipe you may get away with not having a fan to cool your graphics card down.

Other products

Thermal paste: This is a vital product in any PC builders' kit. It’s normally applied between a processor and the heat sink and helps conduct the heat away from the processor. Too much of the paste is counter productive, you need only a thin film.

Chassis Fans: The most popular size of chassis fan is the 80 mm. However, 120 mm fans are now becoming quite popular – and therefore available - because they do tend to generate less noise. Not all 120 fans may fit on your case as the case may have screw holes for only the 80 mm size. There may be adaptors available that will allow you to use a 120 mm fan in a location normally reserved for an 80 mm. Some of these chassis fans are quite clever; they come with ducting that leads to the CPU to provide a more direct route for CPU heat to leave the case.

In quality cases you will normally have at least one or two chassis fans at the front of the case drawing cool air in. Often this air is dragged in over a dust filter or a grill. This air movement through the filter/grill can cause a small bit of noise. In our opinion it’s not worth removing an intake filter to reduce sound. The filter does serve an important purpose. Removing a filter may well save you a fraction of sound but the extra dust going into your PC and settling on fan bearings will more than negate that benefit.

Chassis fans range from about 15 dba to about 30 dba. Quality case manufacturers who provide chassis fans tend to provide fans that generate less than 20 dba.

Regulators: Most electronic shops will stock a variety of devices that can control fan speeds via resistances. It is possible to have all the fans in your PC, from your PSU to the CPU to the chassis fan running only at the lowest rpm they need to run to keep the relevant parts within your pre-defined operating temperature range. Automatic adjustments of power to a fan can make it spin faster or slower and these automatic adjustments could be based on the output readings from temperature sensors. These are all products for the professional or the very keen enthusiasts. Attempting to fit them yourself may result in some burnt out components before you get fully familiar with them and fully competent at setting them up.

Poweroid: UK quiet PC specialists, more info and prices on quiet PCs