Re: RAID card recommendation - Mailing list pgsql-performance

From Greg Smith
Subject Re: RAID card recommendation
Date
Msg-id 4B1D70E5.5060803@2ndquadrant.com
Whole thread Raw
In response to Re: RAID card recommendation  (Scott Carey <scott@richrelevance.com>)
Responses Re: RAID card recommendation  (Craig James <craig_james@emolecules.com>)
Re: RAID card recommendation  (Karl Denninger <karl@denninger.net>)
List pgsql-performance
Scott Carey wrote:
> 9650 was made by 3Ware, essentially a PCIe version of the 9550. The 9690SA
> was from some sort of acquisition/merger. They are not the same product line
> at all.
>
3ware became a division of AMCC, which was then bought by LSI.  The
9590SA came out while they were a part of AMCC.

I was under the impression that the differences between the 9650 and the
9690SA were mainly related to adding SAS support, which was sort of a
bridge addition rather than a fundamental change in the design of the
card.  You'll often see people refer to "9650/9690" as if they're the
same card; they may never run the same firmware.  They certainly always
get firmware updates at the same time, and as part of the same download
package.

Another possibility for the difference between Scott's experience and
mine is that I've only evaluated those particular cards recently, and
there seems to be evidence that 3ware did some major firmware overhauls
in late 2008, i.e.
http://unix.derkeiler.com/Mailing-Lists/FreeBSD/performance/2008-10/msg00005.html

Let me try to summarize where things are at a little more clearly, with
the data accumulated during this long thread:

-Areca:  Usually the fastest around.  Management tools are limited
enough that you really want the version with the on-board management
NIC.  May require some testing to find a good driver version.

-3ware:  Performance on current models not as good as Areca, but with a
great set of management tools (unless you're using SAS) and driver
reliability.  Exact magnitude of the performance gap with Areca is
somewhat controversial and may depend on OS--FreeBSD performance might
be better than Linux in particular.  Older 3ware cards were really slow.

One of these days I need to wrangle up enough development cash to buy
current Areca and 3ware cards, an Intel SSD, and disappear into the lab
(already plenty of drives here) until I've sorted this all out to my
satisfaction.

--
Greg Smith    2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com  www.2ndQuadrant.com


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