From owner-freebsd-scsi Fri Apr 14 13:56:25 1995 Return-Path: freebsd-scsi-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id NAA05589 for freebsd-scsi-outgoing; Fri, 14 Apr 1995 13:56:25 -0700 Received: from husky.cs.vt.edu (jaitken@cslab.cs.vt.edu [128.173.41.87]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id NAA05579 for ; Fri, 14 Apr 1995 13:56:22 -0700 Received: (jaitken@localhost) by husky.cs.vt.edu (8.6.10/8.6.4) id QAA31915; Fri, 14 Apr 1995 16:54:53 -0400 From: Jeff Aitken Message-Id: <199504142054.QAA31915@husky.cs.vt.edu> Subject: Re: SCSI target To: nate@trout.sri.MT.net (Nate Williams) Date: Fri, 14 Apr 1995 16:54:52 -0400 (EDT) Cc: rgrimes@gndrsh.aac.dev.com, freebsd-scsi@FreeBSD.org In-Reply-To: <199504141951.NAA29549@trout.sri.MT.net> from "Nate Williams" at Apr 14, 95 01:51:19 pm X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 2422 Sender: freebsd-scsi-owner@FreeBSD.org Precedence: bulk > > > Your not going to get much more out of *any* ISA controller. The 1542CF > > will do a little better, but basically your problem is the speed of > > the ISA bus bus mastering (typical max is 5MB/sec *burst*, sustainted > > goes down to about 3.7-4MB/sec). You should be getting about 3MB/sec > > out of your 1542B and I have not seen anthing better on ISA. > > I *should* be seeing 3MB/sec, but I've never got #'s even close. > > This is with 2.0R install created FS's. > > Writing the 32 Megabyte file, 'iozone.tmp'...31.257812 seconds > Reading the file...24.953125 seconds > > IOZONE performance measurements: > 1073473 bytes/second for writing the file > 1344698 bytes/second for reading the file Maybe I'm just not understanding something here, but shouldn't I be getting better than 3MB/s with both the NCR Fast-SCSI2 controller + a Micropolis Fast-SCSI2 drive? (486DX2/66, 16MB, PCI/ISA, 256K cache) % iozone 32 IOZONE: Performance Test of Sequential File I/O -- V1.16 (10/28/92) By Bill Norcott Operating System: POSIX 1003.1-1988 -- using fsync() Send comments to: norcott_bill@tandem.com IOZONE writes a 32 Megabyte sequential file consisting of 65536 records which are each 512 bytes in length. It then reads the file. It prints the bytes-per-second rate at which the computer can read and write files. Writing the 32 Megabyte file, 'iozone.tmp'...16.140625 seconds Reading the file...10.984375 seconds IOZONE performance measurements: 2078880 bytes/second for writing the file 3054742 bytes/second for reading the file % iozone 128 IOZONE: Performance Test of Sequential File I/O -- V1.16 (10/28/92) By Bill Norcott Operating System: POSIX 1003.1-1988 -- using fsync() Send comments to: norcott_bill@tandem.com IOZONE writes a 128 Megabyte sequential file consisting of 262144 records which are each 512 bytes in length. It then reads the file. It prints the bytes-per-second rate at which the computer can read and write files. Writing the 128 Megabyte file, 'iozone.tmp'...59.031250 seconds Reading the file...42.664062 seconds IOZONE performance measurements: 2273672 bytes/second for writing the file 3145920 bytes/second for reading the file -- Jeff Aitken jaitken@vt.edu