Data Backup Digest

A fairly recent addition to the hard drive market is drives that have been designed to be energy efficient. Hitachi Global Storage Technologies and Western Digital are two companies that have released drives in the market, with their products boasting a reduced power consumption of up to 40% over a standard hard drive.
Usual power consumption of a hard drive in a desktop computer is between 5 and 15 W, so you would be forgiven for thinking that having an energy saving hard drive isn’t particularly important. Indeed, for the home user it probably isn’t. However, in something like a data centre, where there are thousands of hard drives storing enormous amounts of data all operating at once, it becomes more relevant. It doesn’t just apply to computers either, with equipment like set-top boxes and home theatre PCs needing to be as cool and quiet as possible.
The big area that consumes power on a hard drive is the physical, mechanical parts that make it up. The spindle motor and the actuator will see increased power consumption depending on how fast they are working. Variants can include the number of platters and how big they are. When in a server environment, something called Native Command Queuing can come in to play. This is something which analyses all commands and reorders them in order to reduce head movement, thus saving energy.
Another area on the hard drive which consumes power is the circuit board, which carries the controller, cache memory and interface logic. Although improved integration over time have meant the hard drive core logic is becoming more efficient, it is still something to consider.
Decreasing how fast the spindle operates and reducing acceleration and break performance on the actuator can be beneficial for power saving. Using lighter materials can also help. However, manufacturers should approach this with caution, since hard drives will still need to remain robust. Smooth rotation of the platters is something that is very important and should not be undervalued. On the logical side of things, temporarily disabling functions such as cache memory when it is not in use can help save energy.
Technology website Tom’s Hardware performed tests on the Hitachi Deskstar P7K500 and the Western Digital Cavier GP back in 2008. According to their results, both devices reduce the average idle power consumption by up to 50% and the maximum power requirements by 20% to 30%. They noted that power savings of 3-5 W on a standard hard drive are slight for home users. However, consumer devices which need to be cool and quiet, like personal video recorders, do benefit. Also, companies with huge numbers of hard drives will see a difference due to the cost reduction in power requirements and cooling.
For the home user it doesn’t seem important to purchase an energy saving hard drive. Other components on your computer, like the graphics card or processor, produce more energy. If performance and cost is similar to that of a standard hard drive then you may want to consider it, but it seems that those most likely to reap the rewards of an energy saving drive are large companies with thousands of drives operating all at once.