Date: Tue, 3 Jun 1997 17:52:38 +0200 (MEST) From: Søren Schmidt <sos@sos.freebsd.dk> To: gibbs@plutotech.com (Justin T. Gibbs) Cc: luigi@labinfo.iet.unipi.it, toor@dyson.iquest.net, hackers@FreeBSD.ORG Subject: Re: DMA for IDE drives ? Message-ID: <199706031552.RAA10984@sos.freebsd.dk> In-Reply-To: <199706031502.JAA04331@pluto.plutotech.com> from "Justin T. Gibbs" at "Jun 3, 97 09:58:58 am"
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In reply to Justin T. Gibbs who wrote:
> Do the newer IDE drives support any concept similar to tagged queueing?
> Perhaps via EATA? Supporting DMA is only half the battle in my mind as you
> won't get anywhere near the throughput of a SCSI drive if you can't
> schedule and have the drive reorder multiple transactions at a time.
There seems to be provision for queued overlapped DMA in the
newest ATA pseudo std. A depth up to 31 is possible. I havn't
checked deeper yet what the drives are capable of doing with
the queue though...
I'm currently playing with using DMA on my Maxtor drives, I'll
look closer when I get the time....
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Søren Schmidt (sos@FreeBSD.org) FreeBSD Core Team
Even more code to hack -- will it ever end
..
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