From owner-aic7xxx Fri Feb 13 14:18:07 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA20971 for aic7xxx-outgoing; Fri, 13 Feb 1998 14:18:07 -0800 (PST) (envelope-from owner-aic7xxx@FreeBSD.ORG) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA20957 for ; Fri, 13 Feb 1998 14:18:03 -0800 (PST) (envelope-from gibbs@narnia.plutotech.com) Received: (from gibbs@localhost) by narnia.plutotech.com (8.8.8/8.7.3) id PAA09267; Fri, 13 Feb 1998 15:15:10 -0700 (MST) Date: Fri, 13 Feb 1998 15:15:10 -0700 (MST) From: "Justin T. Gibbs" Message-Id: <199802132215.PAA09267@narnia.plutotech.com> To: Andrew Reilly cc: aic7xxx@FreeBSD.ORG Subject: Re: SCSI Specs & Comparisons - answers (long) (fwd) Newsgroups: pluto.freebsd.aic7xxx In-Reply-To: <199802112247.JAA10525@gurney.reilly.home> User-Agent: tin/pre-1.4-971204 (UNIX) (FreeBSD/3.0-CURRENT (i386)) Sender: owner-aic7xxx@FreeBSD.ORG Precedence: bulk >> This is not correct. The "default" speed is 3.3 Mo/s, which is the maximum >> asynchronous operation speed. If the devices so negotiate, they can operate >> synchronously at 5 Mo/s. > > Is the asynchronous rate is limited like that? I've read blurbs from > Symbios that claim that they've achieved 7MHz asynchronous operation > between two of their more recent controllers. Maybe there is a limit in > the definition, and Symbios were just blowing steam? There is no "defined" limit on the asynchronous transfer rate. It is essentially controlled by the signalling speed of the two devices and the length of the cable. 3.3MB/s is a "good guess" for about how fast two average speed devices will communicate in a typical cabling environment. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message