Making better use of energy, space and resources isn’t just a self-aggrandizing, feel-good project. Green IT  forces IT workers to challenge conventions and push toward innovation by constantly reaching for devices, IT plans and technology that consume less energy, use recyclable materials and take up less space.
One of the clunkier pieces of technology in IT is the old hard-disk drive, which can be a bit of an energy hog. Today’s HDDs are nowhere near the size they were in, say, 1956, but they could stand to be a lot greener.
Hu Yoshida , a vice president and CTO for Hitachi, recently took to his blog to highlight two green options in storage: Solid-state drives (SSDs) and small form factor (SFF) disk drives.
Small Form Factor Disk Drives
A 2.5-inch disk drive uses about half the power of a 3.5-inch disk drive. So moving from 2.5-inch drives to 3.5-inch drives provides a significant reduction in power. While the SFF drive may not hold as much capacity as a 3.5-inch drive, it can be spun at a faster RPM and still consume less power. A common practice with 3.5-inch drives is short stroking, where data is written only to a portion of the tracks in order to reduce track seek time. This can be eliminated with SFF drives as well as with new capabilities, like page-level tiering.
Since solid-state drives are not mechanical, they consume less power and generate less heat than spinning disks — however, they are very expensive. This higher cost can be mitigated if they are used with automated page-level tiering, where a small percent (less than 10%) combined with large-capacity spinning disk will require less spindles of spinning disks to achieve the same or better performance than a single tier of high performance disks. Fewer spindles mean less power and cooling.