Managing Size, Heat, and Noise
Asetek’s Solution to a Mounting Problem

n interesting dichotomy is evolving in the world of the PC.  Desktop form factors are shrinking while processor power is on the rise.  This leads to a need to increase airflow across a processor that is housed in a tightening space.

Removing heat from the system poses no real technical challenge – all that is needed is to accelerate the airflow.  This does cause one difficulty that has not been a problem until now – fan noise rises until it becomes objectionable.

An option once available to users – that of moving the PC away from the display and keyboard – is becoming unfeasible as video interfaces improve.  The move to HDMI or DVI limits separation to about 3 meters.

ow loud is loud?  Some PCs today idle at about 30dBA increasing to 36dBA under load.  30dBA is about the sound level of a quiet conversation or a loud whisper.  In future PCs the sound level could rise to 30dBA at idle but 46dB under load. (Some workstations today reach a full 52 dBA under load).  Although a 10dBA difference doesn’t sound that large, we remind the reader that the decibel is a logarithmic unit of measure: Every 3dB increase represents a doubling of volume, so a 40dBA noise level is ten times as loud as the 30dBA one.  A 3dB volume difference is sufficient to drown out the quieter sound.

And, by the way, that 40dBA sound is about as loud as a crowded lobby full of people conversing.

NEC has gone so far as to wrap soundproof padding around the HDDs of their Valuestar X VX780/GD so that disk noise wouldn’t be heard.  A recent C-Net article (http://crave.cnet.com/8301-1_105-9890211-1.html) touts the silence of a laptop with a solid-state drive.  The second approach is simpler than the first, since the blanketed HDD had to be attached to a liquid cooling system – the padding blocked airflow that was critical to cooling the HDD.  Too bad that the cost of a gigabyte of SSD is about 20 times that of an HDD gigabyte!

Another pricey way of reducing the heat in the box is to purchase a low-power CPU.  Such chips can provide similar throughput to their more power-hungry counterparts, but this advantage comes at a premium.

 new solution has been brought to our attention.  Start-up Asetek has introduced an inexpensive liquid cooling system that moves the heat from the system’s processor to a radiator.  Since the radiator is several times the area of the CPU heat sink, the air used to remove the heat can be in a far less concentrated stream than one blowing at cooling fins mounted directly to the CPU itself.  This, in turn, dramatically reduces noise.  The cooler, which should increase the PC’s costs by around $10-30 is far lower than the $150-250 typical of other liquid cooling systems.  Asetek tells us that the system is maintenance free (50K hours of system life, with 100K hours for the pump) eliminating the support burden endemic to older discrete liquid cooled solutions.  Size and weight meet the OEM requirements, as opposed to many aftermarket solutions that violate weight or size limits that the OEM cannot tolerate.

While it may be too early to determine if this is the wave of the future, we are certainly intrigued that a very simple liquid cooling system could solve problems of PC noise at a very reasonable price.  We plan to watch this company and see how users and OEMs respond to their solution.