Harddisk speed: PIO4 vs. UDMA66 controller ?

[Kris Kennaway]

On Wed, Dec 08, 2004 at 09:41:15PM +0900, Rob wrote:

> > ad0: 43979MB <IBM-DTLA-307045/TX6OA50C> [89355/16/63] at ata0-master PIO4
> > acd0: CDROM <CRD-8520B/1.00> at ata1-master PIO4
> >
> >The harddisk is very new and can do UDMA100. With a UDMA66 controller
> >I expect the harddisk to operate at least at 66 MB/sec. Any ideas why
> >the speed is only PIO4?
> 
> I just realize that I have put in /boot/loader.conf:
> 
>   hw.ata.ata_dma="0"
> 
> to prevent a WRITE_DMA panic at bootup.
> That's probably the reason why the harddisk speed is forced
> to PIO4, right?

Yes.

Kris
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