Molex SilentDrive Acoustic Enclosure

A high proportion of noise created by PCs comes from the hard drive(s). This is because the magnetic platters in the hard drive spin constantly at high speed. In addition, the heads moving back and forth across the platters cause “clicking” noises every time files are accessed by the operating system.

Much research and development has been done by drive manufacturers in recent years to try to make hard drives quieter, but despite this, the noise most drives make is still very noticeable and distracting, even when using hard drives which are specifically marketed as being quiet. The obvious solution is to enclose the drive in an acoustic sleeve and this is how the SilentDrive works.

As you would imagine, the main problem associated with enclosing a hard drive is that of cooling; excessive heat is not healthy! The SilentDrive fully addresses this issue by having two aluminium “cold plates” which cover both the top and the bottom of the drive and conduct unwanted heat safely away into the surrounding air and chassis mountings.

Thermal compatibility

The SilentDrive has the ability to work safely with all 7200 rpm or lower hard drives. This is based on the assumption that the hard drive dissipates a maximum of around 7-8 watts of heat, and the objective is to keep the running temperature under the 60-65°C recommended maximum which is specified by most hard drive manufacturers. Because drive heat dissipation is almost entirely related to spindle speed, unfortunately the SilentDrive is not compatible with 10,000 or 15,000 rpm drives.

Enclosing a hard drive will typically increase its running temperature by around 3-5°C. For peace of mind, it is sometimes useful therefore to be able to monitor the temperature of your hard drive “real time” within Windows, to ensure that the drive is not overheating. For hard drives which support this feature, you can use a free program called DTemp to display the drive temperature in your Windows system tray. We would recommend setting DTemp’s “Critical Temperature” setting to around 60-65°C, in line with most manufacturers’ specifications. Click here to download DTemp.

Physical compatibility

The SilentDrive works with all 3.5” hard drives which have a standard height of 1 inch (2.54 cm), which covers virtually all modern drives. 1.6 inch high drives are not catered for, because they would not fit into the enclosure while still allowing the product to fit into a 5.25” drive bay, and the heat dissipation from such drives would be higher anyway due to the increased friction of a taller spindle. Please ensure your hard drive is 1 inch high (maximum) before ordering a SilentDrive since the product will not work with 1.6 inch high drives!

Performance

The primary design goal of the SilentDrive is to reduce the medium and high-frequency air-borne “whirring” noise of the spindle bearings, which it does with exceptional success. This is the type of noise which most people find annoying in a hard drive, because it is always there in the background. With a SilentDrive installed, the difference is remarkable!

The airborne noise reduction achievable through installation of a SilentDrive is highly impressive. The typical noise level in a quiet room is 28 dBA. Bearing in mind that an increase of 3 dBA means a doubling in acoustic power, you will appreciate that the loudest hard drives (in the 36-38 dBA range) will make a big difference to the sound level in a room. You can expect a SilentDrive to reduce the noise of these drives to below 30 dBA. Quieter hard drives will be mitigated to 28 dBA or less, meaning that their sound will be barely perceptible above the background level of noise in the room.

The Register SilentDrive / Ultra-Quiet PSU review