Hybrid disk drives

Samsung have announced a hybrid hard disk for use with Windows Vista. The announcement is here http://www.samsung.com/PressCenter/PressRelease/PressRelease.asp?seq=20060517_0000255266

Basically, the disk just has more cache memory, 128MB or 256MB, but crucially, can use the cache as an extension of the hard disk as a staging area. This allows (dependent on traffic type) for the hard disk to be left spun down for longer periods. Samsung are pitching the device as offering benefits to laptops and to reduce boot speeds for Windows systems.

That's all great for Windows, but what about wider usage? It seems to me that the benefit of having a larger more intelligent cache is great for a PC based operating system where the working set of data on a large disk may only be a few hundred megabytes. Larger systems will probably have access profiles of more random read/write or even significant sequential access.

It may be that with intelligent microcode, midrange and enterprise arrays can benefit from the ability to leave devices spun down, potentially saving power and cooling. That would be a great benefit in today's datacentres.