Re: FreeBSD 5.3b7and poor ata performance

From: fandino <fandino_at_ng.fadesa.es>
Date: Sat, 16 Oct 2004 19:46:39 +0200
Hello Kevin,

Kevin Oberman wrote:
>>Tests were done win bonnie++ 1.93c and the results were Linux two
>>times faster than FreeBSD using the same hardware.
>>
>>GNU/Linux 2.4.18 with ext2:               56848 K/sec
>>FreeBSD 5.3b7 with default fs:            26347 K/sec
>>FreeBSD 5.3b7 ata raid0* (two disks):     26131 K/sec
>>FreeBSD 5.3b7 geom stripe* (two disks):   30063 K/sec
> 
> 
> Are you comparing apples with apples? I believe that Linux mounts file
> systems as async by default. To compare with FreeBSD, you should use "-o
> async" when you mount. Of course, this is less reliable.
>
> Also, make sure that disk write-cache is enabled on both or disabled on
> both. 

write-cache was enable on all tests and disks were in UDMA5 mode.

In this new round of tests I add FreeBSD witch async and OpenBSD (always
using the same hardware). FreeBSD is by far, the worst throughput of all
(about 50% slower than others) :-?

GNU/Linux 2.4.18 with ext2:               56848 K/sec
FreeBSD 5.3b7 with default fs:            26347 K/sec
FreeBSD 5.3b7 with default fs(async):     26566 K/sec
FreeBSD 5.3b7 ata raid0* (two disks):     26131 K/sec
FreeBSD 5.3b7 geom stripe* (two disks):   30063 K/sec
FreeBSD 5.3b7 geom stripe** (four disks): 31891 K/sec
OpenBSD 3.5 UFS fs:                       55277 K/sec

* Each disk of the raid had a throughput of approx. 15000 K/sec
** Each disk of the raid had a throughput of approx. 7500 K/sec
Each disk of the read split the throughput by half.

How is possible that FreeBSD performs as bad?


http://195.55.55.164/tests/bsd.txt       (original FBSD test)
http://195.55.55.164/tests/obsd.txt      (openbsd test)
http://195.55.55.164/tests/gstripe-4.txt (4 disks gstripe tests with async)
http://195.55.55.164/tests/fbsd2.txt     (FBSD test with async)
http://195.55.55.164/tests/linux.txt     (original GNU/Linux test)
http://195.55.55.164/tests/dmesg.txt
Received on Sat Oct 16 2004 - 15:46:41 UTC

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