An external drive that drops its power down in three stages as inactivity time lengthens has been announced by Kanguru. It is an 80 - 750GB capacity product, connecting to Windows or Mac systems by USB 2.0.
Kanguru's Eco Drive automatically gauges hard drive usage to reduce power consumption. The three power-saving modes include:
* Idle mode (drive operates at 80 percent of normal consumption after three seconds of inactivity),
* Standby mode (drive operates at 10-20 percent of normal consumption after three minutes of inactivity), and
* Power Down (drive operates at 5-10 percent of normal consumption after five minutes of inactivity).
Spin-up takes longer the deeper the power-saving mode. The three power modes are configurable through included software for Windows platforms: Windows 2000; XP; and Vista. The drive is compatible with Mac OSX as well. SATA, meaning external SATA, support will be available soon.
Kanguru reckons that Eco Drive's power usage can go up to 75 percent lower than existing external drives and extends the life of the hard drive itself. For a USB-connected external drive such a power-saving scheme is practical as file or record access is likely to be infrequent and mostly by the user doing drag-and-drop or backup operations.
It wouldn't be practical for a workstation's main disk as that would be used for application swap space, and response speed is critical for good performance. However, micro-management of power supplies to such disks can achieve a lot. Western Digital's IntelliSeek technology achieves a smoothing out of drive head movements so that the head reaches the next target sector just in time to read the next piece of information, rather than rapidly accelerating and waiting for the drive rotation to catch up.
Western Digital reckons that this alone could reduce drive power usage by 60 percent or so compared to existing drives.
Such a form of power saving would also be best for RAID drive arrays where activity levels on individual drives cannot be used to gauge the likelihood of the drive being needed as RAID data striping will spread file and/or record information randomly across drives such that highly active files and databases will need all drives spinning all the time for fast response to applications.
The need for online drive performance will, in other words, rule out activity-level based power-saving modes such as that used by Kanguru's new drive.
The Eco Drive is available, with 80GB capacity, for $99.74 on CDW-G . A 750GB unit will cost about US$350.