From owner-freebsd-scsi  Thu Aug 22 15:37:38 1996
Return-Path: owner-freebsd-scsi
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id PAA24252
          for freebsd-scsi-outgoing; Thu, 22 Aug 1996 15:37:38 -0700 (PDT)
Received: from insanus.matematik.su.se (root@insanus.matematik.su.se [130.237.198.12])
          by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id PAA24194
          for <scsi@freebsd.org>; Thu, 22 Aug 1996 15:37:17 -0700 (PDT)
Received: from localhost (tege@sophie.matematik.su.se [130.237.198.29]) by insanus.matematik.su.se (8.7.5/8.6.9) with ESMTP id AAA15687 for scsi@freebsd.org; Fri, 23 Aug 1996 00:37:32 +0200 (MET DST)
Message-Id: <199608222237.AAA15687@insanus.matematik.su.se>
X-Address: Department of Mathematics, Stockholm University 
	      S-106 91  Stockholm
	      SWEDEN
X-Phone: int+46 8 162000
X-Fax:   int+46 8 6126717
X-Url:   http://www.matematik.su.se
To: scsi@freebsd.org
Subject: Adaptec 2940UW sync at low rates
Date: Fri, 23 Aug 1996 00:37:06 +0200
From: Torbjorn Granlund <tege@matematik.su.se>
Sender: owner-freebsd-scsi@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

When the 2940UW is set in "Ultra mode", it refuses to talk at lower than 10
MB/s to any devices.  Unfortunately, I have a Toshiba 6.7x CD-ROM drive, and
a HP DAT drive that max out at 4.4 MB/s and 5.0 MB/s respectively.  FreeBSD
warns about these devices, but to my surprise, at least the CD-ROM seems to
work great!  (I haven't tried the DAT drive yet.)

My first stupid question is: Can I ignore this problem, or will it cause
serious problems with the devices that I simply haven't run into yet?

My second stupid question is: Can an ASUS SC200 coexist with an 2940UW?
Which one's boot ROM will win...?  :-) (The boot ROM for the SC200 is on the
ASUS motherboard.)

My third stupid question is: If one uses several similar SCSI controllers
(say an 2940UW and a plain 2940), which one will be ahc0 and which one will
be ahc1?

My last stupid question is: Are there (FreeBSD-supported) Ultra SCSI
controllers that support more speeds than the 2940UW?  I'll run out of PCI
slots if I am forced into using two SCSI controllers.

Torbjorn