Date: Sun, 24 May 1998 22:39:20 -0700 From: Mike Smith <mike@smith.net.au> To: Amancio Hasty <hasty@rah.star-gate.com> Cc: Philippe Regnauld <regnauld@deepo.prosa.dk>, Luigi Rizzo <luigi@labinfo.iet.unipi.it>, current@FreeBSD.ORG Subject: Re: ATAPI CDDA Extraction under FreeBSD Message-ID: <199805250539.WAA10671@antipodes.cdrom.com> In-Reply-To: Your message of "Mon, 18 May 1998 09:36:03 PDT." <199805181636.JAA04038@rah.star-gate.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> How many outstanding dma requests can the IDE bus handle? The issue isn't the bus but the controller(s) and drive(s). I'm not aware of any drives on the market that support more than a single outstanding transaction (although the standard allows for drives to support tagged transactions). > For instance do you expect to be able to read audio CDs while > doing heavy i/o on the IDE disks? This depends on the relative priorities attached to I/O to the disk/ CDROM. If the two are serviced fairly, and the net throughput is less than the capacity of the bus, then all should be fine. Otherwise, it would probably be necessary to modify things so that the CDROM is preferentially serviced or the CDROM will overrun. ie. no different from the SCSI case. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199805250539.WAA10671>