Clearly, we are going through a period of time dedicated to hard disks. Not long after Western Digital announced its ground-breaking storage density for 3.5-inch HDDs, Hitachi is now touting the "world's most energy-efficient desktop hard drive."

The P7K500 is designed for desktop computers and has 7200 RPM and a Serial-ATA interface. Based on the second-generation perpendicular magnetic recording (PMR), enabling 250GB-per-platter areal density, the new product comes in capacities ranging from 250GB to 500GB.

The new Desktar P7K500 uses a set of power-saving technologies that translate into a power consumption 40 percent lower in idle mode than the previous models. Also, the unit is said to be 59 percent more power efficient than comparable 250GB hard drives in its class.

Here's a more detailed explanation from Hitachi's press release: "Through a 40-percent power reduction, Hitachi GST has delivered unmatched idle power utilization of 3.6 watts on the 250GB capacity model and 4.8 watts on models with capacities of 320GB or greater. Similarly, the P7K500 has reduced its active power requirements to 6.4 watts and 8.2 watts for its one- and two-disk models, respectively."

This performance was achieved by using the company's HiVERT technology, which was first pioneered with the Hitachi Travelstar mobile products. The Deskstar P7K500 hard drive increases the use of switching regulators in place of linear regulators for more efficient voltage conversion in the electronics. The drive has also adopted the Travelstar system-on-chip design with a more power-efficient profile, which further reduces power consumption.

Finally, all of the Deskstar hard drives incorporate Hitachi GST's Advanced Power Management capabilities, which have been implemented for six product generations. These capabilities significantly lower the power consumption of hard drives while in idle mode, which is most of the time.

"Energy expenses related to IT hardware in the data center and in the office are becoming a significant cost for organizations," according to John Rydning, IDC's Research Manager for hard disk drives. "IT hardware component suppliers will need to do their part to help improve the overall power consumption of PCs, servers and storage systems, and Hitachi GST's next-generation HDDs with reduced power consumption is a step in the right direction," Hitachi's press release quotes Mr. Rydning as saying.

The Deskstar P7K500 will be available in high volume later in 4Q 2007.

Here are some more technical specifications:

250/320/400/500GB

185 billion bits per square inch maximum areal density

2/1 platters, 4/2 recording heads

1138 Mb/s max. media data rate

7200 RPM, 4.17 ms average latency

PATA-133 and 3Gb/s SATA

8 MB (single disk)/8MB and 16MB (two disk) data buffer

26.1 mm in height (max)

550 in weight (max)

350 G/2 ms non-operating shock

3.6/4.8 watt idle power

2.6/2.8 Bels typical idle acoustics

0 to 60 degrees C ambient temperature (operating)