How to enable DMA on a SATA drive (was dd backup unbelievably slow on SATA laptop)

[Kevin Kempter]

On Thursday 04 January 2007 10:52, Alan wrote:
> > > hdparm -d1 <device>
> >
> > I've yet to run across any SATA controllers which allow one to enable
> > or disable DMA support via hdparm.
>
> The SATA drivers always enable DMA when possible.  A dmesg is really
> needed to see what is going on.

Should I grep for something specific or just attach an output after a bootup 
of dmesg?