Hybrid Disk Drives (HDD), the combination of a standard hard disk drive and a NAND chip, are a budding phenomenon enabled by new features of Microsoft’s Windows Vista operating system. It is different from standard hard drives in that it employs a large buffer of non-volatile flash memory to cache data during normal use.

A new report shows that this technology promised to sweep the PC hard drive market. However, some say Hybrid Hard Drives have been a disappointment for consumers, and the makers admit Hard Drives with cache fall short of expectations.

Xbit Laboratories writes that manufacturers promised that the Hybrid Hard Drives would cut down power consumption, increase battery life, and, most importantly, speed-up boot-up time.

However, the actual performance increase of HHDs is not crucial and customers are reluctant to pay extra for them. Dr. Richard New, director of research for Hitachi Global Storage Technologies says: “The initial versions haven’t delivered the performance consumers expected.”

The problem, says New, might be correctable if drive makers put in more flash. Right now, hybrid drives have about 256MB of memory. If you put in 4GB or so, the flash could hold a lot more storage, which in turn would reduce power consumption and help boot-up time.

According to Fujitsu Computing Products of America, Hybrid Hard Drives with small cache ensure boot-up time drop from 28 seconds with a standard drive to 21 seconds with a hybrid. However, the company believes that consumers are not going to pay for such a small advantage.

Perhaps we have to wait and see whether the Hybrid Hard Drive’s advanced capabilities will be supported by other operating systems, which currently limit their support to Microsoft Windows Vista.