Rotating hard drives will remain the best choice for high density storage in the foreseeable future, thanks to new read/write head technology from Hitachi that is expected to deliver four terabyte (4TB) desktop drives.

Hitachi Global Storage Technologies said it has developed new read/write heads that are about 30-50nm in size. Known as current perpendicular-to-the-plane giant magnetoresistive (CPP-GMR), the technology is expected to appear in shipping products by 2009.

According to Hitachi, CPP-GMR heads will enable hard disk recording densities of 500 gigabits per square inch. This is approximately four times as high as current technology used in the company’s first one terabyte drive, unveiled earlier this year. A terabyte is approximately one thousand gigabytes.

"Hitachi continues to invest in deep research for the advancement of hard disk drives as we believe there is no other technology capable of providing the hard drive’s high-capacity, low-cost value for the foreseeable future,” said Hitachi's research director, Hiroaki Odawara.