How to Build a Powerful Quiet Computer

You could make your computer quieter by making it less powerful. But that's basically just giving up part of your computer to get rid of part of its noise. Instead of bothering you a little by making noise as it works, your computer could bother you a lot by making you wait for it to work. Here's how to build a computer that is both very quiet and very fast.

Steps

1. Understand a few principles of computer cooling
• Moving parts get much noisier as they move a little faster. Two big, slow fans will be quieter than and move as much air as a big medium-speed fan, or one or more small or medium-size medium-speed or fast fans.
• Air flows more easily thorough a large continuous space than through a series of narrow spaces with the same total cross-section. A heatsink with very-closely-spaced fins is for maximum performance with a powerful fan, to make sure most of the air molecules bump into it and carry away heat before they're blown out and away. It's not better with a slow fan, but moderately-spaced, thin, smooth fins as most heatsinks are usually fine. A given amount of energy (and noise) will much more easily suck in cool air or blow out hot air through a big fan and open grate than a lot of little fans and little holes.
• Heat needs to be removed from components, and from the case. Exhausting it to the outside directly avoids unnecessary work and noise removing it with a separate fan.
• Don't rely on the power-supply fan for removing much heat from the inside of the computer. The power supply needs to be kept cool too. If most of the rest of the computer's heat has to flow through the power supply, the power supply's life will simply be shortened and/or its not-easily-replaceable and not-necessarily-very-quiet fan will automatically increase speed.
• Most components need at least a little cooling. One or more case fans for a flow pattern eliminating dead spots is best. If you have multiple expansion cards and some produce much heat (see if they have heatsinks on them, or if they feel hot after use), direct a fan to cool them directly. As usual, a big quiet fan, mountable directly on some cases, is preferable.
• Mechanical components such as fans and hard drives should be soft-mounted so that they cannot transfer their vibration to the wide case panels, which efficiently transfer it to large amounts of air and make noise. Isolated, these components dissipate vibration mostly as negligible amounts of heat within themselves.
• A fan sucks air in from all directions toward one side, then blows it out the other in a narrow stream. So, it's more effective to blow air toward something to be cooled a distance away, or to create an overall draft. If the fan is directly against something, such as a heatsink, the direction is not very important and should be chosen to assist rather than fight overall air flow. Sometimes fans can be noisy when one side or another is obstructed due to the fan pushing against its bearings. Using wire fan grills, rather than grates, can reduce the unwanted back pressure.

2. Choose a case.The "tower" type is best because it can go under a desk, distancing the computer from the ears, while allowing the removable-disk drives to be reached easily and not consuming much floor space. Look for the following features:
• Large vents to let air in toward the front (often holes around the sides of a plastic bezel and a perforated steel plate behind it) and preferably a front fan mount. Big exhaust fans at the back won't do much good unless air can easily flow into and throughout the computer before blowing out.
• All-120mm fan mounts. This is the standard "big" fan size. Fans bundled with cases might be quiet enough, particularly if their speed is adjustable, but don't count on it.
• Unobstructed fan openings. Grids of little round holes are bad; large perforations making an open mesh is good.
• Plenty of width, so a big CPU cooler protruding off the motherboard will fit. Most mid-size and full towers are pretty wide.
• Long video card compatibility, at least 10.5 inches.
• Plenty of 5.25 inch hard drive bays, if you will use hard-drive enclosures. Otherwise, built-in 3.5 inch bay hard-drive soft mounts, such as those Antec provides, are nice.
• A ventilation hole and fan mount arrangement to cool the expansion cards.
• Aluminum cases, possibly due as much to being fancy overall, with little vibration-damping plastic and also with fancy loose rattle-prone tool-less connectors rather than screws, tend to be noisy. (Gaps that tend to rattle against each other can be muffled by applying cloth tape or even foam weatherstrip to the mating surfaces.) Steel is quieter. Almost all computer cooling is done by fans, not conduction through the case, so a steel case will keep cool just as well.
• "Acoustic damping foam" can absorb (not just seal in) noise from interior components. It is applied to inside surfaces of a computer. If you choose to use it, check that it does not interfere with interior components such as case hard-drive racks or a big heatsink.
• One author likes Antec cases with 120mm fans.

3. Choose a motherboard. Full ATX is best for a quiet PC because it lets expansion cards be spaced out for better cooling. These boards also happen to more often have features making them better for other reasons, too.
• Look for a motherboard with multiple-GPU technology, such as AMD "Crossfire" or nVidia "SLI", compatible with your type of video card if you think you might want to upgrade. SLI compatibility is more restricted.
• It's often easiest to mount the CPU cooler before installing the motherboard in the case. If the cooler does not clip to the CPU socket or a bracket around it as most do but uses screws extending through the motherboard (tighten only firmly, don't break something), you must have access to the back of the motherboard to mount it.

4. Choose a CPU cooler. This will generally be a heatsink with an attached fan, also known as a "HSF" or simply a "heatsink". Look for standard 120mm fan compatibility. As with a case, a bundled fan may be quiet enough, but don't count on it. A "tower" style heatsink is generally quietest; check that the case will be wide enough to accommodate it hanging off the motherboard. Generally avoid all-copper heatsinks because they cool only very slightly better than copper-and-aluminum ones, and are so heavy they risk damaging the motherboard when the computer is moved.
• The CPU cooler will need a mount compatible with your particular kind of CPU. Many are compatible with many kinds of CPUs, but check.
• A CPU cooler's fins are often thin metal with sharp edges. Take care not to drag fingers against them or hold them by the edges of only a few fins. It would be best to hold the cooler with a glove or small towel if force, such as pressure on a clip, is needed to mount it (be careful not to break anything). CPU coolers with only a few thin, sharp fins placed a significant distance apart could increase the risk of cuts.
• Be sure to remove any plastic film from over the CPU and heatsink, and Apply Thermal Paste, also known as thermal compound, when installing a heatsink. Modern CPUs generally have a large metal protective "heat spreader" permanently installed. The recommended small blob of thermal paste in the middle to be spread by pressure is fine; bear in mind that the actual CPU is a small chip under the middle of the plate so perfect edge-to-edge coverage is unneeded, and trying to achieve it by spreading the compound risks more-problematic bubbles. If the heatsink base has crevices in it, such as those around heatpipes that touch the CPU directly, fill them with thermal compound (scrape it in with an unneeded plastic card). The thermal paste that comes with a cooler is generally fine, but check reviews if you like.
• One author likes Arctic Alumina. It's no more effective than other good thermal pastes, but it's relatively easy to clean up and non-conductive so an errant bit won't cause problems.
• The cooler supplied very cheaply by the CPU manufacturer would be effective, but they are, with some exceptions, loud (check reviews of the kind supplied with your specific model of CPU). Generally, you won't want to use it. You may as well not try it because the single-use thermal pad (rather than thermal paste) it comes with is hard to clean off when you remove the cooler.
• One author likes the Sunbeam Core-Contact Freezer. It's effective, cheap, and not very heavy, but the mounting clip requires considerable pressure. The bundled fan is fairly quiet; the cooler is a bargain even if another fan is used.
• Some heatsinks such as Thermalrights are available with matching ducts to exhaust hot air directly. You'll need a case fan hole straight behind the heatsink. These can be inconvenient to install.
5. Choose fans. Slow-moving 120mm fans are best. Bigger, slower fans are available, but not in many varieties. Ball bearings are very durable but noisy. Sleeve bearings are less durable, particularly in high-temperature environments (which should not be a problem if the case is ventilated by multiple 120mm fans). Fluid bearings (FDB) are quiet and durable but cost a little more. Some fans have special blade designs to reduce turbulence noise, but that isn't much of a problem with slow fans anyway. Retail stores tend to have high markups on fans and other small accessories.
• One author likes the Scythe S-Flex 800rpm, which has fluid bearings.
• Check the CPU temperature with monitoring software to make sure it isn't too high. 60 degrees Centigrade or below under sustained load is fine (extreme cooling isn't necessary except for overclocking).

6. Mount and arrange fans. Use soft mounts instead of screws. Arrange the fans so air flows through the case in an orderly manner. For instance, in at the lower front and by the expansion cards, through the CPU cooler, and out the back. There should be a case exhaust fan, but air can also be pushed out by the power supply fan, a duct from the CPU cooler, and a video card integrated heatsink.

7. Choose video cards. Look for something that has a dual-slot cooler (which has room for a much bigger, slower, quieter fan) and exhausts hot air out of the case directly. Multiple video cards would generally be better than dual-GPU cards, because less air must be forced through the little heatsinks to cool them. Look for a relatively inexpensive current card that has the same kind of cooler the manufacturer supplies on its most powerful card. These will generally be almost as capable as, but significantly less power-hungry and noisy than, the best if they have almost as many parallel processing units running at a slightly lower speed and voltage.
• Non-standard dual-slot heatsinks are often not as quietly effective as the chip manufacturer's reference heatsink, which is generally the most common kind. But they are usually better than single-slot coolers.
• Unlike CPUs, video cards are not designed for a variety of coolers. Aftermarket coolers generally occupy multiple slots and are difficult and somewhat risky to install.
• If you use multiple video cards, try to space them out. Try to avoid covering one's air intake with an adjacent card.

8. Choose hard drives. A solid-state drive is extremely fast, cool-running, and completely silent, but expensive in large capacities. If you need a lot of storage, 5400 RPM or slightly faster hard drives with fluid bearings (which most of them have now) are best. They are cheap, nearly silent, and only a little slower than the common faster 7200 RPM drives. A more complicated approach would be to use the 5400 RPM drives for data storage, and the SSD for programs, where its fast random access is particularly advantageous.
• You can reduce the latency of a slower-spinning hard drive with "short-stroking" to reduce seek time at the expense of capacity. You can do this with a special drive-configuration program, or simply by making only a single small partition of perhaps 25% of the drive's capacity.This partition should be at the "beginning" of the drive, customarily mapped to the higher-linear-speed, higher-data-rate outer tracks. (A very small partition is wasteful because rotational latency is constant at a given RPM.)
• Like fans, hard drives should be soft-mounted to keep them from transferring vibration to the case. The kind of soft mount for a hard drive is different from the kind for a fan. Some Antec cases come with soft mounts. They may also come with "suspension" mounts, but moving the computer with those in place risks serious damage.
• Do not wrap hard drives in insulating material. The best way to quiet them is a padded enclosure with special heat-conducting parts. One author likes the "Smart Drive" from Grow Up Japan.

9. Choose a power supply. A power supply converts alternating current from the mains into direct current at various voltages your computer can use. Power supplies vary in capacity, efficiency (which affects quietness because waste energy becomes heat which needs to be removed by airflow), noise, and consistency of power output. They include fans and heatsinks, which are not practical to change. Look for a well-recognized brand name or favorable reviews specific to the particular model, a 120mm or larger fan, sufficient connectors for all your components (extras can be added for items that consume little power, like CD drives), and good ratings for quietness ("silent" in the description means little). As a rule of thumb, choose one with a capacity rating of about twice the total maximum power consumption of the major system components (CPU and video cards) for long life and quiet operation, and one with "80 Plus" efficiency certification.
• "80 Plus" bronze, silver, gold, and platinum are successively higher levels of efficiency certification.
• Fanless power supplies are not great for high-power computers. They would need cooling from external fans, which would be a less efficient, louder use of air flow.
• Power supplies with "modular" cables can give a neater appearance, but add a set of power-supply-to-cable connections to potentially have problems. If your concern is simply quietness, just neatly bundle excess cables to reduce airflow obstructions.
• One author likes Antec (economical but good), Enermax (high capacity) and Nexus (super quiet) power supplies. 

source : http://www.wikihow.com/

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