is it possible to lower 7200rpm to say 4200rpm HD?

[dan]

the toshiba and samsung notebook drives are very quiet, i wonder if it is possible to lower the rpm of an HD from 7200rpm to say 4200rpm only when desired -- not permanently.

when, for example, reading text or listening to music or watching dvd. it should be even more silent and cooler running at the lower rpm. 7200rpm is fine for boot-up, and initial application loading, 4200rpm when doing passive activities like word processing or web-browsing. it should be a program.

[geforce1]

I don't think it's possible to "under- or over-rev" a hard disk drive. If I'm not mistaken, in the review of the Hitachi 7K250, the "under-rev" mode on that particular drive is a low-power standby mode designed for faster recovery from said mode.

[Tzeb]

the toshiba and samsung notebook drives are very quiet, i wonder if it is possible to lower the rpm of an HD from 7200rpm to say 4200rpm only when desired -- not permanently.

when, for example, reading text or listening to music or watching dvd. it should be even more silent and cooler running at the lower rpm. 7200rpm is fine for boot-up, and initial application loading, 4200rpm when doing passive activities like word processing or web-browsing. it should be a program.

That's odd.....today i was just thinking about something similar
How dificult would be for manufactures to implement a feature that would allow the drive to go at half the speed when the user desire? I have in mind an aplication jist like WinAAM or any other AAM tool for windows.
Open application, 1 click - drive goes at 3000, 4200, 5400, whatever, when browsing or downloading stuff at night When performance is desired you can switch back to maximum speed.
Would this be sometime posible?

[wsc]

IMHO this would not be possible with just a single piece of windows software. At the very least the microprocessor(s) on the drive would need new or modified firmware. Not a trivial task by any stretch of the imagination. There are multitudes of less sadistic solutions for a silent drive... all IMHO of course.

[Jan Kivar]

I'm afraid it's not possible. The head/slider assembly is designed to float above the platters, and the correct flying height is maintained by an air bearing. This air bearing is generated from the spinning platters (Bernoulli effect?), and is proportional to the rotation speed. Should the speed drop below specified minimum, the drive retracts the heads from the data area to prevent a head crash (this happens also if power is suddenly lost).

Cheers,

Jan