Date: Fri, 14 Apr 1995 16:54:52 -0400 (EDT) From: Jeff Aitken <jaitken@cslab.cs.vt.edu> To: nate@trout.sri.MT.net (Nate Williams) Cc: rgrimes@gndrsh.aac.dev.com, freebsd-scsi@FreeBSD.org Subject: Re: SCSI target Message-ID: <199504142054.QAA31915@husky.cs.vt.edu> In-Reply-To: <199504141951.NAA29549@trout.sri.MT.net> from "Nate Williams" at Apr 14, 95 01:51:19 pm
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>
> > 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
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