RE: More disk arms myth exploded...

["Ingvaldson, Scott" <SIngvaldson@xxxxxxxxxxxx>]

I'll second that guess and add the new disk controller as well.  As far as
the disk arms are concerned, a 6532/6533 controller has a 4MB write cache,
versus the new 2757 with 757 MB write cache.  It doesn't mean that the
number of arms doesn't matter, just that the effects are lessened if you
have the cache.

Regards,

Scott Ingvaldson
iSeries System Administrator
GuideOne Insurance Group

-----Original Message-----
date: Fri, 13 Aug 2004 10:49:01 -0500
from: "Jones, John (US)" <John.Jones@xxxxxxxxxxxxxxxxxxxxxxx>
subject: RE: More disk arms myth exploded...

 
I would guess #1: Tape controller.  On our 730 using 3580-H23 drives,
saves at 70GB/hour over a 6534.  On our 830 using the same drive types
but a 2729, we get 200GB/hour.  The machines have similar RAM, CPW, #
disk arms, etc.  And really, more than the tape controller it's the SPD
bus.

You could also potentially mention the spreading of the data will be
optimal on the 520 as it was a reload. But I don't think it would make
that large of a difference.

John A. Jones
Americas Security Officer
Jones Lang LaSalle, Inc.
V: +1-630-455-2787 F: +1-312-601-1782
John.Jones@xxxxxxxxxxxxxxxxxxxxxxx

-----Original Original Message-----
From: rob@xxxxxxxxx [mailto:rob@xxxxxxxxx] 
Sent: Friday, August 13, 2004 10:06 AM
To: midrange-l@xxxxxxxxxxxx
Subject: More disk arms myth exploded...

<snip>

Don't know if it:
1)      was the difference between the 6534 and the 2749 card
2)      the way we have them configured (do we have the tape card on the

520 not sharing a processor with disk and not the same on the 820?)
3)      or the difference between the 520 and the 820

<snip>

Rob Berendt
--
Group Dekko Services, LLC
Dept 01.073
PO Box 2000
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
   
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