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I've noticed that when I change the sleep time for my laptop running Windows 7 both for battery and plugged in, the timer on turning off the hard drives is not updated.

Why wouldn't the hard drives be turned off at the same time the laptop goes to sleep?

Should I update this manually and make sure the hard drive is turned off as the computer goes to sleep?

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up vote 1 down vote accepted

Why wouldn't the hard drives be turned off at the same time the laptop goes to sleep?

They are, you're correct. What you're getting hung up on, though, is that the hard drives can be turned off BEFORE the computer goes to sleep. They don't have to be constantly spinning for the machine to operate. That's the reason for a separate timer; if you want them to spin down but still have the machine running. (These days, there aren't a lot of scenarios where you can go for extended periods of time without accessing a drive at all, but they do exist.)

My personal recommendation is to set your drives to never spin down unless the machine is asleep (so change that setting to 0 minutes, which registers as 'Never'), but then my personal recommendation is also to never sleep your machine so I may perhaps be biased. Modern computers don't really consume that much less power at sleep than idle - as long as the MONITOR(s) is(are) sleeping you're probably fine. (Obviously if you run a laptop on battery a lot, you may want to ignore this advice for battery operation.)

EDIT: Read the comments for a bit more discussion on this, it seems I could have worded this better.

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May I ask how you came to conclude "computers don't really consume that much less power at sleep than idle"? – Louis Jul 21 '12 at 13:04
@Louis - The power consumption for most modern components is specified very clearly by the manufacturers, you can look this stuff up yourself. Reading this a year later, I maybe would have worded it a bit differently - there's a notable difference, but idle is still dramatically lower than at load, so unless your power bill is a major concern that's not a compelling reason to sleep the system. The only thing, IMO, in the standard desktop PC that uses enough power to maybe convince me to sleep it is tf you have a high powered GPU. – Shinrai Jul 21 '12 at 14:43
Ah, I see what you were saying. Since I was thinking in an idle system, an HDD that wasn't sleeping could alone, nearly account for the ~5W consumed by a sleeping computer. I also had a discrete graphics in mind when I downvoted. I see now, how there are systems that have very low idle power consumption though (I found an example at 28W). Sorry, it's too late to undo the downvote. – Louis Jul 21 '12 at 15:12
@Louis - I normally wouldn't do this, but since you've expressed a desire to change your vote I'll make a minor edit. :) – Shinrai Jul 21 '12 at 17:17

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