CNET reader Georg Frausing asks:
It is difficult to find some of the tested laptops with the lowest noise level. Any suggesting how to find them?
The noisiest parts of a laptop are likely to be its internal fans, the hard disk drive, and the optical drive. The hotter a laptop's internals get, the louder the fans are likely to be. (Note: not all laptops have internal fans.) You can actually play around with this on a MacBook using the freeware utility, smfFanControl. Depending on how good a job the laptop manufacturer did designing the laptop, sometimes a spinning hard disk drive causes a laptop to emit noise via sympathetic vibrations. Some optical drives can be noisemakers as well--especially when they spin up to speed or spin down. This can be especially annoying during the quiet portions of a DVD movie. CNET Labs does not conduct noise tests on laptops, and I know of no sites or publications that regularly do this type of testing.
You could conduct anecdotal testing yourself, but the results would be very limited in usefulness. Assuming you could even get access to all the laptops you wanted to compare, you would need to test them in an environment that was fairly well protected from environmental noise. When we toyed with this type of testing ourselves, the best we could do was an environment of about a 30 dbA--a far cry from the coveted 10 to 20 dbA range typically found in professional anechoic chambers. At the laptops section of a Best Buy, you'd be hard-pressed to detect the whine of a spinning fan over the din of your fellow shoppers and that man in the audio section blasting The White Stripes.
But let's assume that your best friend is an acoustical engineer with access to a space conductive to this type of testing. To test how noisy the fans are, you'd want the laptop to be operating a heavy workload for an extended period of time. A good way to do that would be to play as high-end a game as the laptop supports at the highest playable settings for at least a half hour with the room's air conditioning turned off. You would measure the noise using a sound pressure meter. You'd want to hold the meter at the exact same angle and distance from each laptop to test each one the same way. One of the many problems with this approach, however, is that you wouldn't necessarily be using the same workload on each laptop, so you wouldn't stress all of the laptops the same way. To test the hard disk noise, choose a workload that uses lots of nonsequential disk seeks--such as defragmenting a heavily fragmented hard drive.
Another variable mucking up the works is that no two laptops of even the same make and model are guaranteed to have identical characteristics. Minor variations in manufacturing--especially over time--can render different results on different units.
I've attended many conferences where industry pundits put out a call to manufacturers to focus more on acoustic issues in regards to computer design. The attendees all nod their heads in agreement, but I can't say I've really seen (heard?) laptops get any quieter. These same evangelists also call for improved thermal designs, but many recent laptops I've used still manage to actually warm my lap to uncomfortable temperatures.
This is a simple question with a complicated answer. Using earplugs or headphones is not the answer when you are trying to spare others the noise from your laptop. For instance, being a new dad, I've had to adjust my computing behavior at home so as not to wake my daughter with a noisy computer.
So how does a consumer identify a relatively quiet or especially noisy laptop? A Google search of the text "quiet laptops" points you to a number of user-contributed forums where real-world users chime in with their own acoustic experiences. If the noise level of a laptop is an important purchasing decision for you, we want to know. Perhaps we'll revisit doing this type of testing. Post a comment and let us know how important this is to you.