How to enable NCQ on freebsd 8.1 ?

Alexander Motin mav at
Tue Jul 27 17:31:51 UTC 2010


Nickolay Krylov wrote:
> I have enabled "options ATA_CAM" in the generic kernel and now can't understand
> NCQ works or not.

"options ATA_CAM" enables wrapper for existing ata(4) controller
drivers, that do not support command queuing. All this option give to
you is switching to newer bus management and peripheral code.

> ada0 at ata2 bus 0 scbus2 target 0 lun 0
> ada0: <ST31000524NS SN11> ATA-8 SATA 2.x device
> ada0: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
> ada0: 953869MB (1953525168 512 byte sectors: 16H 63S/T 16383C)

If NCQ was supported, you would also see there lines:
ada0: Command Queueing enabled

> This system installed on Tyan Tomcat K8E motherboard.

To support MCQ you should use one of new drivers: ahci(4), siis(4) or
mvs(4) on supported hardware. As I can see, your board is based on
nForce4 chipset, which supports NCQ in own proprietary way, which is not
supported at the moment and unlikely will be ever supported, as it is
quite old already and all later chisets are AHCI compatible instead of it.

Alexander Motin

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