Archive for the ‘pc’ Category

Hello to the world of noiseless Silent PCs!

December 31, 2006

A Silent PC is called a PC , whose noise level was reduced by special measures.

Current computers with high end hardware produce high temperatures. While the first PCs onlyhad an electrical power consumtion of a few Watts and no special cooling of components was needed, the hunt of the manufacturers and consumers for higher performance at lowest prices led to an enormous power consumtion and heat emission of PCs in the meantime. The fact that same performance is possible with substantially smaller energy consumtion also shows e.g. the notebook technology.

For the dissipation of the amounts of heat usually small exhausting fans are used, which cause substantial noise. This problem can be reduced or eliminated by modification and correct choice of the components purchased. Passive cooling concepts, which get along completely without fans, promise complete avoidance of exhausting noise.

 

Power Supply

The fans of standard power supplies are mostly very loud, since they run in each operating phase with the highest speed. Here the noise level can be very strongly reduced by a temperature-controlled cooling fans. In addition there are silent power supplies to be mentioned, which are equipped mostly with one 120 mm or 140 mm fan which is able to push larger air volumes at lower speeds more. However these power supplies are mostly clearly more expensive. If the pc already has a noisy power pack, a change of the power pack exhausting fan to a quieter (running in ball bearings) model will make sense. The change should be made exclusively by a specialized company, since mortal danger exists. A more expansive solution is to replace the power supply to a passively cooled model.

The Processor Cooling

At first here should be noticed that a processor cooler with a very good heat dissipation (e.g. with copper core) should be used. With the CPU purchased Standard Processor coolers are in most cases not adjustable, and will run in the normal operation with constant 12 V. Various manufacturers offer coolers with adjustable fans, which make an operation possible with 12 V and with 7 V. The noise level sinks with the jump from 12 V to 7 V over approx.. 30% while offering approximately the same cooling performance. Also a passive cooling or water cooling is possible, however at a clearly higher price.

System Cooling

Here should be already paid attention at the purchase to a good and quiet cooling, because with a modification immediately any warranty gets lost. Here something similar applies as for the processor cooling that a loud cooling not automatically means also a good cooling performance. Meanwhile some very good and quiet cooling fans are available but the best and a noiseless system would only be possible with passive cooling.

Harddisk damping

If one has undertaken the measures mentioned above, then one will notice that the non removable disks transfer their vibrations to the housing. The non removable disk manufacturer Seagate indicates the fact that approximately 70% of the sound produced by a non removable disk as impact sound is delivered to the case. For this reason an uncoupling is usually an amazingly effective way to get a non removable disk more quietly.

But there are finished bays and mounting plates, in which by rubbers the non removable disks are separated from the housing. Some solutions offer also additional cooling functions for the Harddisk Drive. The uncoupling is quite effective, when the non removable disks do not have a direct contact to the housing and and pass on their oscillation energy.

A quite favorable solution are conventional rubbers, with which an uncoupling for under 50 cent per non removable disk is possible.

Such self-‘s building solutions can be high-grade dangerous however, if the used elastomer does not withstand the endurance stresses by heat, stretch, electromagnetic fields and ozone. Straight conventional household rubbers, as rubber seals, O-ring seals from the sanitary area, or elastic strips from the clothing industry are absolutely unsuitable.

A rise in temperature of the non removable disk by a flexible suspension actually is not to be expected usually. The non removable disk in a flexible suspension can deliver no more warmth to the (metallic) disk cage, but this heat dissipation hardly plays a role in practice. Positively however the suspension affects the direct air cooling, since the non removable disk can be flowed around by all sides.

Northbridge Cooling

Main board manufacturers again and again equip the Northbridge with an active radiator. Partially in order particularly to address Overclocker, in addition, due to the high calorific loss achievement of current chips. Due to the mostly small measured place on the motherboard, here frequently very fast running 40 mm fans are used. The exchange of these coolers usually cause the immediate loss of the warranty.

Completely Silent PCs

Some companies already offer complete PCs that were designed after acoustic objectives.

Totally noiseless and passive cooled computers are available at zalman or sizo.

Noise Measuring

In the computer range two different standarts are common for the classification of the noise emission by the equipment: The decibel scale, and the Sone scale.

The decibels, usually in the ‘ A’-weighted form (dBA), is a logarithmic scale. This means above all that the scale is not linear. Therefore a direct or intuitive comparison of two different (A) measured values is hardly possible. In addition it comes that the railway (A) scale, despite a weighting, which is taken to the human aural acuity only something over the soundness (more exact: , however nothing states the sound pressure level) of a noise over its subjectively felt as annoying.

Exactly this, much ‘ human ‘ criterion is however crucial with relatively quiet interferences. As example (subjective) the comparison between the summ of a mosquito and murmuring of a river is mentioned: Although the latter with a far higher -(A)-worth -measured, everyone will classify the summ of a mosquito as substantially more disturbing.

Therefore the decibel scale is only very conditionally suitable to make statements about the noise emission (or their absence) with computers.

Measured values are more meaningful in the sone scale, which also evaluates other factors, that play a role for the human auditory sensation. With Sone actually applies:

double value = twice as loud (and annoyingly)
To the selection of components for silent PCs, the values of the following table can apply as an orientation, whereby it is to be made sure that only such measured values are comparable, which were determined under same conditions. The weightiest factor of influence is the microphone distance to the acoustic source.

Valuation Range normal PC Range silent PC
very well 0-0.5 Sone 0-0.5 Sone
well 0.5-1.5 Sone 0.5-1.0 Sone
means 1.5-2.5 Sone 1.0-1.5 Sone
badly 2.5-4.0 Sone 1.5-2.0 Sone
very bad starting from 4,0 Sone starting from 2,0 Sone
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