[ANNOUNCEMENT] Wiki for discussing P35/IHC9(R)/SATA issues set
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.
>> Thanks! Like Aryeh, I missed the jumper. I'll test this out tonight
>> I get home.
> 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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