[Pm-utils] Basic powersave hooks

[Stefan Seyfried]

Stefan Seyfried wrote:

> Actually, spindown does not really save much power.

And to provide some numbers (from my Toshiba MK1011GAH, but other drives i
checked last year were similar):

Power Consumption:
Start       1.8 W
Seeking     1.1 W
Reading     1.0 W
Writing     1.0 W
Idle        0.3 W
Standby     0.12 W
Sleep       0.07 W

What you are achieving by spindown is the difference between "Idle" and
"Standby", which is 0.18W.

What you need to consider is, that the disk will spin up in the not too
distant future (and consume much more power during startup, unfortunately i
have no numbers on how long this takes) anyway if the machine is used for
anything remotely useful, so the saving in practice will be much lower.

...and waiting for the disk to spin up all the time is really annoying ;-)

Have fun,

	Stefan
-- 
Stefan Seyfried
R&D Team Mobile Devices            |              "Any ideas, John?"
SUSE LINUX Products GmbH, Nürnberg | "Well, surrounding them's out."

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