Date: Sat, 08 Nov 1997 04:23:50 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: Stefan Esser <se@freebsd.org> Cc: hackers@freebsd.org Subject: Re: Seagate Cheetah performance... Message-ID: <199711081223.EAA02770@rah.star-gate.com> In-Reply-To: Your message of "Sat, 08 Nov 1997 11:45:21 %2B0100." <19971108114521.06151@mi.uni-koeln.de>
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Hi,
I have 48MB of main memory since I am mostly concerned with
comparing my IDE driver to my scsi drive the 96MB file size for Bonnie should
be okay.
This is on my Scsi Seagate Cheetah 4.3gb (10000 rpms)
bonnie -s 96
File './Bonnie.2607', size: 100663296
Writing with putc()...done
Rewriting...done
Writing intelligently...done
Reading with getc()...done
Reading intelligently...done
Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
96 9536 87.8 9446 28.7 3997 13.8 4464 91.5 11518 19.3 163.8 3.3
This on my Ultra DMA IDE drive 3.1Gb -- I think is a fujitsu drive.
bonnie -s 96
File './Bonnie.2631', size: 100663296
Writing with putc()...done
Rewriting...done
Writing intelligently...done
Reading with getc()...done
Reading intelligently...done
Seeker 1...Seeker 2...Seeker 3...start 'em...done...done...done...
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
96 5812 52.7 5769 15.2 2166 6.5 5704 56.5 5746 10.1 81.4 1.6
> On 1997-11-07 22:26 -0800, Amancio Hasty <hasty@rah.star-gate.com> wrote:
> > Well,
> >
> > I found a way to nearly double my performance:
> >
> >
> > iozone 48
> >
> > IOZONE: Performance Test of Sequential File I/O -- V2.01 (10/21/94)
> > By Bill Norcott
> >
> > Operating System: FreeBSD 2.x -- using fsync()
> >
> > Send comments to: b_norcott@xway.com
> >
> > IOZONE writes a 48 Megabyte sequential file consisting of
> > 98304 records which are each 512 bytes in length.
> ^^^^^^^^^ This is where
> your problem originates!
>
> Reading 512 byte blocks is not a typical situation at all ...
>
> > It then reads the file. It prints the bytes-per-second
> > rate at which the computer can read and write files.
> >
> >
> > Writing the 48 Megabyte file, 'iozone.tmp'...5.523438 seconds
> > Reading the file...4.921875 seconds
> >
> > IOZONE performance measurements:
> > 9112377 bytes/second for writing the file
> > 10226112 bytes/second for reading the file
>
> This is > 20000 SCSI commands ! SCSI overhead must be lower than 50us !
> Wow! What are you complaining about ? :-)
>
> > > Any tweaking that I do to improve the performance of my :
> > > <SEAGATE ST34501W 0017> type 0 fixed SCSI 2
> > >
> > > iozone 48
>
> > > IOZONE performance measurements:
> > > 5418377 bytes/second for writing the file
> > > 7828008 bytes/second for reading the file
>
> Again: You are using a much to small transfer rate !
>
> > > My Ultra DMA IDE disk generates about 8MB/sec for writing .
>
> IDE overhead is much smaller than SCSI, there is no arbitration
> for a shared bus, for example.
>
>
> Please test all three drives with Bonnie. Use a test file at
> least twice as much as your system's RAM, and report your
> findings ...
>
> You'll get a different picture, I assume !
>
> Regards, STefan
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