List of fake vs. real SATA drives.

Søren Schmidt sos at DeepCore.dk
Mon Nov 22 20:54:38 GMT 2004


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.

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

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

-- 

-Søren




More information about the freebsd-hackers mailing list