Date: Sat, 15 Aug 1998 11:40:49 -0700 From: Jason Thorpe <thorpej@nas.nasa.gov> To: Mike Smith <mike@smith.net.au> Cc: hackers@FreeBSD.ORG Subject: Re: TESTERS WANTED for new ATAPI CD/CDR/CDRW driver. Message-ID: <199808151840.LAA05693@lestat.nas.nasa.gov>
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On Sat, 15 Aug 1998 11:53:23 +0000 Mike Smith <mike@smith.net.au> wrote: > I'd be curious to know if anyone's measured the cost of the SCSI<->ATA > translation for ATA disks, since that's where performance is really an > issue. Nobody cares how efficient access to a Zip disk is, but an > extra 10% overhead on ATA disk transactions would really hurt. We're not doing it for ATA, but then again ATAPI disk aren't ATA. We are, however, doing a SCSI-like layer for ATA. > Command passthrough doesn't (can't) work directly, as many fields are > different sizes. I think what you mean is that there's no need for any > intelligence in the translation, which is fair enough. ...this doens't really matter if you're, e.g., passing mmc commands to an ATAPI CD-ROM or CD-R. They're the same for SCSI and ATAPI. Jason R. Thorpe thorpej@nas.nasa.gov NASA Ames Research Center Home: +1 408 866 1912 NAS: M/S 258-5 Work: +1 650 604 0935 Moffett Field, CA 94035 Pager: +1 650 940 5942 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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