Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 18 Feb 1999 23:24:21 +0100
From:      Paul van der Zwan <paulz@trantor.xs4all.nl>
To:        freebsd-current@FreeBSD.ORG
Subject:   Slow seq. write on Seagate ST36530N
Message-ID:  <199902182224.XAA00605@trantor.xs4all.nl>

next in thread | raw e-mail | index | archive | help

I am having some performance problems on my -current ( update last weekend)
I hooked up a new Seagate ST36530N yesterday ( connected to an Adaptec 2940U)
and sequential write is very slow.
Compared to an IBM DORS-32160 connected to the same controller ( even the same 
cable) it is half as fast.
Iozone auto shows the following :

Seagate
        IOZONE: Performance Test of Sequential File I/O  --  V2.01 (10/21/94)
                By Bill Norcott

        Operating System: FreeBSD 2.x -- using fsync()

IOZONE: auto-test mode 

        MB      reclen  bytes/sec written   bytes/sec read      
        1       512     5835553             22369621            
        1       1024    3627506             33554432            
        1       2048    3441480             44739242            
        1       4096    4329604             44739242            
        1       8192    3121342             67108864            
        2       512     3627506             22369621            
        2       1024    4260880             44739242            
        2       2048    3273603             38347922            
        2       4096    4067203             67108864            
        2       8192    4067203             67108864            
        4       512     4161790             21474836            
        4       1024    2354696             35791394            
        4       2048    2418337             38347922            
        4       4096    2418337             59652323            
        4       8192    1988410             53687091            
        8       512     2863311             20259279            
        8       1024    1565221             37025580            
        8       2048    1470879             31580641            
        8       4096    1514445             48806446            
        8       8192    1337162             56512727            
        16      512     2041334             14412641            
        16      1024    1536111             27531841            
        16      2048    1476948             43826196            
        16      4096    1410961             48806446            
        16      8192    1432610             52377649            

IBM
        MB      reclen  bytes/sec written   bytes/sec read      
        1       512     3728270             22369621            
        1       1024    4067203             26843545            
        1       2048    3947580             67108864            
        1       4096    3728270             44739242            
        1       8192    3834792             67108864            
        2       512     4549753             13421772            
        2       1024    4194304             44739242            
        2       2048    3890368             53687091            
        2       4096    4400581             67108864            
        2       8192    3677198             67108864            
        4       512     4129776             21474836            
        4       1024    3532045             44739242            
        4       2048    2451465             53687091            
        4       4096    3016128             59652323            
        4       8192    2870967             53687091            
        8       512     2396745             21053761            
        8       1024    2894182             37025580            
        8       2048    2587329             42949672            
        8       4096    2526451             51130563            
        8       8192    2520520             56512727            
        16      512     3067833             20069940            
        16      1024    2701237             34087042            
        16      2048    3591109             43826196            
        16      4096    2306641             42949672            
        16      8192    3121342             52377649            

Bonnie shows the following:
Seagate
              -------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
          100  3251 44.0  1307  4.0  2285 11.5  5006 69.0  8644 23.0 115.1  4.2
IBM
          100  3333 45.0  2533  8.8  1878 10.1  4244 58.2  5140 19.7  76.4  3.3

If I interpret it correctly the Seagate is faster in everything but sequential
writes. 
dmesg shows the following :

da1 at ahc0 bus 0 target 1 lun 0
da1: <SEAGATE ST36530N 1444> Fixed Direct Access SCSI-2 device 
da1: 10.0MB/s transfers (10.0MHz, offset 15), Tagged Queueing Enabled
da1: 6208MB (12715920 512 byte sectors: 255H 63S/T 791C)
da0 at ahc0 bus 0 target 0 lun 0
da0: <IBM DORS-32160 S82C> Fixed Direct Access SCSI-2 device 
da0: 10.0MB/s transfers (10.0MHz, offset 15), Tagged Queueing Enabled
da0: 2063MB (4226725 512 byte sectors: 255H 63S/T 263C)

Anybody an idea ??

	Paul

-- 
Paul van der Zwan		paulz @ trantor.xs4all.nl
"I think I'll move to theory, everything works in theory..."




To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199902182224.XAA00605>