List of fake vs. real SATA drives.

David Gilbert dgilbert at dclg.ca
Tue Nov 23 04:03:30 GMT 2004


>>>>> "Søren" == Søren Schmidt <sos at DeepCore.dk> writes:

Søren> David Gilbert wrote:
>>>>>>> "João" == João Carlos Mendes Luís <jonny at jonny.eng.br> writes:
>> 
>> 
>> João> IIF they really have command queueing, I do believe.  So, a
>> João> bridged SATA drive will not have command queuing, right?
>> 
>> Well... from what I've read, the WD bridged drives do have queueing
>> because they had an ATA-100 implementation of it.
>> 
>> João> Does FreeBSD already take advantage of this?  How could I
>> check João> if my SATA drivers have command queueing or not?
>> 
>> I'd like to know as well.

Søren> Currently the ATA driver does not support neither TCQ nor NCQ.

Søren> For this to work at all both disk and controller needs to
Søren> support the mode in question. I've just gotten my hands on one
Søren> of the new Promise controllers that supports NCQ, but I still
Søren> need disks to get it going.  I do have a few Raptor's that
Søren> support the TCQ mode but initial testing shows little benefit
Søren> from it so it moved to the backburner...

Do you need direct access to a drive or is access to a machine with a
drive/controller in it sufficient.  Are promise controllers the only
ones to support NCQ so far?  Promise doesn't always have the best
reputation.  We may be able to provide a test machine with remote
access to a drive/controller combination.

-- 
============================================================================
|David Gilbert, Independent Contractor.       | Two things can only be     |
|Mail:       dave at daveg.ca                    |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================


More information about the freebsd-hackers mailing list