From owner-freebsd-scsi Mon Apr 9 10: 3:20 2001 Delivered-To: freebsd-scsi@freebsd.org Received: from relay2.mail.uk.psi.net (relay2.mail.uk.psi.net [154.32.107.6]) by hub.freebsd.org (Postfix) with ESMTP id 572B437B422 for ; Mon, 9 Apr 2001 10:03:17 -0700 (PDT) (envelope-from dbhague@allstor-sw.co.uk) Received: from mail.plasmon.co.uk ([193.115.5.217]) by relay2.mail.uk.psi.net with esmtp (Exim 2.12 #2) id 14mf4M-0006qJ-00 for freebsd-scsi@FreeBSD.ORG; Mon, 9 Apr 2001 18:03:15 +0100 From: dbhague@allstor-sw.co.uk Subject: SCSI transfer sizes, To: freebsd-scsi@FreeBSD.ORG Date: Mon, 9 Apr 2001 18:02:44 +0100 Message-ID: X-MIMETrack: Serialize by Router on Melbourn01/SVR/Plasmon(Release 5.0.6a |January 17, 2001) at 04/09/2001 06:03:00 PM MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org We having been doing performance optimisation on optical drives. These are particularly sensitive to transfer size and we would like your advice as to which adapter card would give us the largest possible transfer size. We have noticed between 3.0 and 4.2 the standard transfer size has changed from 128KB to 60KB. After some experimentation we have taken Adaptec up to 256KB but Symbios only goes to 128KB before we have problems. Could you help by advising us on the adapter that will allow us to use the largest transfer size for each SCSI operation ? Regards Dave To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message