Powering SATA Hard Drives

Does anyone know if it's standard practice for motherboards to put
SATA hard drives in standby or sleep mode when they are shut down?

I would like to leave the drives in a system I'm designing
permanently powered, but this will only work if they are shut down
with the motherboard.

I couldn't find anything useful with Google searches and I haven't
heard back from the motherboard manufacturer yet.

If this is not the best place to ask this question, can someone
please suggest a better place.

-- 
-Mike

Mike Warren wrote:
> Does anyone know if it's standard practice for motherboards to put
> SATA hard drives in standby or sleep mode when they are shut down?
> ...

SATA is more or less ATA over a serial cable. You can locate the
various
ATA standards at www.t13.org, find one of the latest ATAs and look
into the SMART feature definitions.
Basically the answer is that you can do pretty much whatever you
want powerwise with the devices. The default behaviour I have seen
on ATA 2.5" drives is to go to standby after some inactivity time
(10 or 20 minutes, have not measured it), and they respond to start/
stop
(actually stop was "sleep" IIRC).

Dimiter

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Mike Warren wrote:
> Does anyone know if it's standard practice for motherboards to put
> SATA hard drives in standby or sleep mode when they are shut down?
>
> I would like to leave the drives in a system I'm designing
> permanently powered, but this will only work if they are shut down
> with the motherboard.
>
> I couldn't find anything useful with Google searches and I haven't
> heard back from the motherboard manufacturer yet.
>
> If this is not the best place to ask this question, can someone
> please suggest a better place.
>
> --
> -Mike

Didi wrote:

> Mike Warren wrote:
> > Does anyone know if it's standard practice for motherboards to put
> > SATA hard drives in standby or sleep mode when they are shut down?
> > ...
> 
> SATA is more or less ATA over a serial cable. You can locate the
> various
> ATA standards at www.t13.org, find one of the latest ATAs and look
> into the SMART feature definitions.
> Basically the answer is that you can do pretty much whatever you
> want powerwise with the devices. The default behaviour I have seen
> on ATA 2.5" drives is to go to standby after some inactivity time
> (10 or 20 minutes, have not measured it), and they respond to start/
> stop
> (actually stop was "sleep" IIRC).

Thanks for the information. For this to work for me, I need the drive
to spin down as soon as the motherboard shuts down as the machines
will often be moved shortly afterwards.

I haven't been able to find out what documents I may need on that
site after a 5 minute look but I'll put more time into it tomorrow.

-- 
-Mike

> I haven't been able to find out what documents I may need on that
> site after a 5 minute look but I'll put more time into it tomorrow.

Their numbering scheme is indeed not very helpful. The one I could
quickly identify for you  - the copy I had printed 5+ years ago was
within reach :-) - is D1153 , which is ATA-4 (pretty close for what
you
need although supporting still only 32 bit LBN).

But you may be lucky and do without the SMART features.
On 2.5" drives (which I use), I can stop the drive with a "normal"
ATA command, I can see I am referring to it as "sleep" in my
comments; the command code is $E6 (0xE6, that is). The drive
comes out of sleep after that with the first read or (I guess) write
command.

Ouch, just looked at my source - before posting. It is my driver
which wakes the device up, not the R/W command; it issues
an ATA reset to wake the drive up... (which in spite of the name
is quite far from a powerup reset, not sure what it did but most
if not all drive parameters remain intact IIRC).

Dimiter

------------------------------------------------------
Dimiter Popoff               Transgalactic Instruments

http://www.tgi-sci.com
------------------------------------------------------
http://www.flickr.com/photos/didi_tgi/sets/72157600228621276/


Mike Warren wrote:
> Didi wrote:
>
> > Mike Warren wrote:
> > > Does anyone know if it's standard practice for motherboards to put
> > > SATA hard drives in standby or sleep mode when they are shut down?
> > > ...
> >
> > SATA is more or less ATA over a serial cable. You can locate the
> > various
> > ATA standards at www.t13.org, find one of the latest ATAs and look
> > into the SMART feature definitions.
> > Basically the answer is that you can do pretty much whatever you
> > want powerwise with the devices. The default behaviour I have seen
> > on ATA 2.5" drives is to go to standby after some inactivity time
> > (10 or 20 minutes, have not measured it), and they respond to start/
> > stop
> > (actually stop was "sleep" IIRC).
>
> Thanks for the information. For this to work for me, I need the drive
> to spin down as soon as the motherboard shuts down as the machines
> will often be moved shortly afterwards.
>
> I haven't been able to find out what documents I may need on that
> site after a 5 minute look but I'll put more time into it tomorrow.
>
> --
> -Mike