From owner-freebsd-hackers Sat Oct 10 14:45:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA05721 for freebsd-hackers-outgoing; Sat, 10 Oct 1998 14:45:08 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from zippy.dyn.ml.org (sf3-63.ppp.wenet.net [206.15.84.63]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA05708 for ; Sat, 10 Oct 1998 14:45:03 -0700 (PDT) (envelope-from garbanzo@hooked.net) Received: from localhost (garbanzo@localhost) by zippy.dyn.ml.org (8.9.1/8.8.8) with SMTP id OAA06903; Sat, 10 Oct 1998 14:46:31 -0700 (PDT) (envelope-from garbanzo@hooked.net) X-Authentication-Warning: zippy.dyn.ml.org: garbanzo owned process doing -bs Date: Sat, 10 Oct 1998 14:46:29 -0700 (PDT) From: Alex X-Sender: garbanzo@zippy.dyn.ml.org To: Luigi Rizzo cc: hackers@FreeBSD.ORG Subject: Re: how fast are "fast" CDROM drives ? In-Reply-To: <199810101313.OAA16631@labinfo.iet.unipi.it> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sat, 10 Oct 1998, Luigi Rizzo wrote: [...] > I got a 32x ATAPI unit one month ago and there is no way (under > -stable) i can get more than 2.2MB/s by dd'ing from the disk. > Considering i get 5-6MB/s from a raw IDE disk (and from iozone with > large files) on the same machine, i don't think the limiting factor is > CPU or the OS. > > I wonder if anybody is able to exploit the speed of their 24/32/40x > IDE or SCSI drives Well, some of the earlier high speed CDs 12x+ cheat a bit by rotating the disk faster only for certian parts of the disc (the outter edges IIRC). The most inner part of the disc would then be read at somewhere around 6x. - alex To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message