From owner-freebsd-scsi Sat Feb 13 00:25:37 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA11264 for freebsd-scsi-outgoing; Sat, 13 Feb 1999 00:25:37 -0800 (PST) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from alpo.whistle.com (alpo.whistle.com [207.76.204.38]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA11259 for ; Sat, 13 Feb 1999 00:25:34 -0800 (PST) (envelope-from julian@whistle.com) Received: (from daemon@localhost) by alpo.whistle.com (8.8.5/8.8.5) id AAA14620; Sat, 13 Feb 1999 00:16:35 -0800 (PST) Received: from s204m82.isp.whistle.com(207.76.204.82) via SMTP by alpo.whistle.com, id smtpdI14617; Sat Feb 13 08:16:28 1999 Date: Sat, 13 Feb 1999 00:16:08 -0800 (PST) From: Julian Elischer X-Sender: julian@s204m82.isp.whistle.com To: "Kenneth D. Merry" cc: Andre Albsmeier , freebsd-scsi@FreeBSD.ORG Subject: Re: Is CAM slower than the old SCSI layer for JAZ drives? In-Reply-To: <199902130347.UAA38439@panzer.plutotech.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Fri, 12 Feb 1999, Kenneth D. Merry wrote: > Andre Albsmeier wrote... > > I have made an odd observation. Copying a large file from > > my 100MBit net to a 2GB jaz, I noticed that 3.1-BETA took > > a lot more time than it used to under 2.2.8-STABLE. > > Exact (well, as exact as dd can be) measurements told me: > > > > 3.1-BETA: > > 135447409 bytes transferred in 178.638903 secs (758219 bytes/sec) > > > > 2.2.8-STABLE: > > 135447409 bytes transferred in 87.649259 secs (1545334 bytes/sec) > > > > This is nearly exact twice the time for 3.1 than for 2.2.8. > > The network is okay, a dd to /dev/null gives me: > > 135447409 bytes transferred in 13.553990 secs (9993176 bytes/sec) I've heard from several sources (notibly Simon Shapiro) that something in the CAM code is slowing things down. However I don't think it's likely to be a theoretical thing, but possibly an implimentation gothca.. in THEORY CAM should equal or surpass the old system, with many organisational advantages. > > julian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message