Re: FreeBSD 5.3b7and poor ata performance

From: Kenneth Culver <culverk_at_sweetdreamsracing.biz>
Date: Mon, 18 Oct 2004 10:00:45 -0400
Quoting fandino <fandino_at_ng.fadesa.es>:

> 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?
>
>
If you're still using the GENERIC kernel, that could explain it, and judging
from other emails I've seen from you, you're still using the GENERIC kernel.

Ken
Received on Mon Oct 18 2004 - 12:00:55 UTC

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