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Message-ID: <33c6269f05041507437f3e8db3@mail.gmail.com>
Date: Fri, 15 Apr 2005 10:43:47 -0400
From: Alex Turner <armtuk@gmail.com>
Reply-To: Alex Turner <armtuk@gmail.com>
To: Marinos Yannikos <mjy@geizhals.at>
Subject: Re: Intel SRCS16 SATA raid?
Cc: "Joshua D. Drake" <jd@commandprompt.com>,
	"Mohan, Ross" <RMohan@arbinet.com>, pgsql-performance@postgresql.org
In-Reply-To: <425FA27A.8010705@geizhals.at>
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References: <CC74E7E10A8A054798B6611BD1FEF4D30625DA59@vamail01.thexchange.com>
	<425E9DE2.7030005@commandprompt.com> <425FA27A.8010705@geizhals.at>

No offense to that review, but it was really wasn't that good, and
drew bad conclusions from the data.  I posted it originaly and
immediately regretted it.

See http://www.tweakers.net/reviews/557/18

Amazingly the controller with 1Gig cache manages a write throughput of
750MB/sec on a single drive.

quote:
"Floating high above the crowd, the ARC-1120 has a perfect view on the
struggles of the other adapters. "

It's because the adapter has 1Gig of RAM, nothing to do with the RAID
architecture, it's clearly caching the entire dataset.  The drive
can't physicaly run that fast.  These guys really don't know what they
are doing.

Curiously:
http://www.tweakers.net/reviews/557/25

The 3ware does very well as a data drive for MySQL.

The size of your cache is going to _directly_ affect RAID 5
performance.  Put a gig of memory in a 3ware 9500S and benchmark it
against the Areca then.

Also - folks don't run data paritions on RAID 5 because the write
speed is too low.  When you look at the results for RAID 10, the 3ware
leads the pack.

See also:
http://www20.tomshardware.com/storage/20041227/areca-raid6-06.html

I trust toms hardware a little more to set up a good review to be honest.

The 3ware trounces the Areca in all IO/sec test.

Alex Turner
netEconomist

On 4/15/05, Marinos Yannikos <mjy@geizhals.at> wrote:
> Joshua D. Drake wrote:
> > Well I have never even heard of it. 3ware is the defacto authority of
> > reasonable SATA RAID.
>=20
> no! 3ware was rather early in this business, but there are plenty of
> (IMHO, and some other people's opinion) better alternatives available.
> 3ware has good Linux drivers, but the performance of their current
> controllers isn't that good.
>=20
> Have a look at this: http://www.tweakers.net/reviews/557/1
>=20
> especially the sequential writes with RAID-5 on this page:
>=20
> http://www.tweakers.net/reviews/557/19
>=20
> We have been a long-time user of a 3ware 8506 controller (8 disks,
> RAID-5) and have purchased 2 Areca ARC-1120 now since we weren't
> satisfied with the performance and the 2TB per array limit...
>=20
> -mjy
>=20
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