> On Thu, Sep 27, 2001 at 03:35:09PM -0400, Bruce Momjian wrote:
> > > Usually when this question is asked, the response is "well,
> > > I've run a lot of servers, and they just seem faster." But I'm
> > > only interested in hard data.
> >
> > Well, SCSI with tagged queueing allows you to send multiple disk
> > requests to the drive and the drive orders them to be optimal. Only the
> > drive knows there the head it at a given moment so it seems good to push
> > such optimizations into the disk drive.
>
> >From what I gather from reading lkml, recent ATA standards do include such
> capabilities. Whether it is supports by the drivers, controllers and disks
> is another matter entirely. But it is there.
The ATA system basically has the disk controller in the CPU while SCSI
has commands that you send to the drive and the drive implements them.
Not sure how you could implement tagged queueing with the ATA system.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 853-3000
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