[ANNOUNCEMENT] Wiki for discussing P35/IHC9(R)/SATA issues set up

Scott Long scottl at samsco.org
Tue Nov 6 07:59:02 PST 2007

??? Bill Hacker wrote:
> Rusty Nejdl wrote:
>>> Does SATA300, but has the same "feature" as the OP's Seagate drive:
>>> a small jumper that limits the drive to SATA150 unless removed.
>>> See below PDF.
>>> http://www.seagate.com/ww/v/index.jsp?vgnextoid=e2af99f4fa74c010VgnVCM100000dd04090aRCRD&locale=en-US 
>>> http://www.seagate.com/staticfiles/support/disc/manuals/desktop/Barracuda%207200.10/100402371h.pdf 
>> Jeremy,
>> Thanks!  Like Aryeh, I missed the jumper.  I'll test this out tonight 
>> when
>> I get home.
>> Rusty
> BTW - in a recent test of 2.5" high-capacity HDD, it was noted that SATA 
> required significantly more power than PATA. Well 'significant' to a 
> laptop on battery, anyway.

Yes, this is because the SATA physical interface is always transmitting 
a signal, i.e. it has 100% duty cycle, whereas PATA tri-states when it's
not active and typically has a 10-20% duty cycle even when active.  It's
a well understood issue in the SATA world, and drives and controllers 
are starting to appear on the market that address it.

> Given that single-drive setups seldom stress even UDMA 133 over the 
> course of reasonable time spans, does anyone know if:
> A) SATA 300 needs yet-again more power than SATA 150?

Yes, it's a higher frequency so it draws more power.

> B) running down-shifted to SATA 150 might actually be a better plan 
> anyway in some circumstances?

A little better, but still not as good as being able to put the signal
to an idle state.


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