Silence your PC

Posted at: Friday 7th October 2005 by James Morris

A powerful PC doesn't necessarily have to sound like a jet engine. James Morris investigates how to make a high-end PC more acoustically demure

Entirely passively cooled PSUs are also available, but we wouldn't recommend these for a power system. In our power supply Labs test, we found that these PSUs had a tendency to overheat under heavy load, as their heat dissipation is much slower than actively cooled units - for obvious reasons. This can lead to reduced efficiency, or even more dangerous consequences.

For this reason, we opted for a premium Tagan TG480-U01 supply to replace our relatively inexpensive 550W Levicom 550XPE-P PSU in our basic system. This features automatic temperature control and two fans, but the interior 92mm intake fan is on the bottom, so any air has to make a 90-degree turn before exiting, which is hardly optimal.

In contrast, despite being aimed at the power PC user, Tagan's TG480-U01 has a great reputation for low noise. Its fans are fully temperature-controlled with a continuously variable envelope, and they're configured with one fan at the front and one at the back. This means that air can flow directly across the interior components.

However, in practice, the Tagan wasn't much quieter than the Levicom, although we'd certainly recommend spending the extra £14 on the Tagan for its combined noise and power stability benefits.

Well hard

Fans may rotate at a few thousand revolutions per minute, but the fastest spinners in your system will be hard disks. Standard S-ATA drives operate at 7,200rpm, the premium Western Digital Raptor spins at 10,000rpm and the fastest SCSI models top 15,000rpm. A hard disk can be one of the most annoying noise pollutants, particularly when it's being furiously accessed. So, for a quieter system, your best option is to swap your existing squealer for a drive with a lower decibel rating.

Fortunately, we recently discovered a drive that keeps the noise down without having to compromise on performance. When we tested Samsung's new SpinPoint P120S, it not only aced our benchmarks but was also virtually inaudible in the process. With this in mind, we had to find out how it compared with a noisy, powerful beast such as the Raptor.

Although hard drives make a tiny amount of noise when they're idle, the most annoying noise is the random chugging they make when they're reading or writing data. We're sure you're familiar with this if you've ever run a disk defragmenter on a well-established system. For this reason, we sound-tested both the basic system and the quiet system while copying 2GB of files from one directory on the drive to another to ensure maximum disk activity.

Surprisingly, the difference wasn't as huge as you might expect. The noise level went up by 1.6dBA on the basic system when the Raptor was accessing data, but increased by just 0.2dBA when the Samsung drive was performing the same task, a level that is effectively inaudible. One explanation for this is that hard disk noise is actually transient, so, unlike a fan that consistently makes the same noise, a hard drive will only make a noise every now and then. So, as the results of our sound test represent an average amount of noise over a period of time, the effect of the hard disk's transient pings and rattles are mostly camouflaged. However, even though the hard disk doesn't significantly affect the average noise level, the effects can still be noticeable and, on a subjective level, the Samsung is much quieter than the Raptor in operation.