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From: bert hubert <ahu@ds9a.nl>
To: Johannes Ruscheinski <ruschein@mail-infomine.ucr.edu>
Cc: Joel Jaeggli <joelja@darkwing.uoregon.edu>, linux-kernel@vger.kernel.org
Subject: Re: Best Low-cost IDE RAID Solution For 2.6.x? (OT?)
Date: Sun, 28 Dec 2003 22:56:44 +0100	[thread overview]
Message-ID: <20031228215644.GA32140@outpost.ds9a.nl> (raw)
In-Reply-To: <20031228213535.GA21459@mail-infomine.ucr.edu>

On Sun, Dec 28, 2003 at 01:35:35PM -0800, Johannes Ruscheinski wrote:

> Fisrt of all: thanks for the advice Joel!  Two questions: why not use the
> hardware raid capability of the Promise tx4000 and if we'd use software
> raid instead, what would be the CPU overhead?

For the cost differential between linux native RAID and an external device
of similar capabilities, outfit yourself with an additional CPU. I don't use
RAID5 a lot but to a modern CPU, checksumming dozens of megabytes/second is
child's play:

raid5: measuring checksumming speed
   8regs     :  1479.600 MB/sec
   32regs    :   744.400 MB/sec
   pIII_sse  :  1649.200 MB/sec
   pII_mmx   :  1806.000 MB/sec
   p5_mmx    :  1915.200 MB/sec
raid5: using function: pIII_sse (1649.200 MB/sec)

This is on a 800MHz Celeron, so a recent >2Ghz system will do lots better
still.

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://lartc.org           Linux Advanced Routing & Traffic Control HOWTO

  parent reply	other threads:[~2003-12-28 21:56 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-12-28 18:04 Best Low-cost IDE RAID Solution For 2.6.x? (OT?) Johannes Ruscheinski
2003-12-28 18:50 ` Joel Jaeggli
2003-12-28 21:35   ` Johannes Ruscheinski
2003-12-28 21:45     ` Arjan van de Ven
2003-12-28 22:14       ` Johannes Ruscheinski
2003-12-28 23:05       ` H. Peter Anvin
2003-12-29  1:18         ` Wakko Warner
2003-12-28 21:56     ` bert hubert [this message]
2003-12-28 23:36     ` Joel Jaeggli
2004-01-07 23:28       ` bill davidsen
2003-12-29  2:10 ` Samuel Flory
2003-12-29 13:41   ` Tomas Szepe
2003-12-29 18:59     ` Johannes Ruscheinski
2003-12-29 19:04       ` Samuel Flory
2003-12-29 19:06         ` Tomas Szepe
2003-12-30  0:03         ` Wakko Warner
2003-12-30  6:54           ` Tomas Szepe
2003-12-30 14:41             ` Wakko Warner
2003-12-30 20:58               ` Samuel Flory
2004-01-07 23:35               ` bill davidsen

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