820 - 520 upgrade

Well with all the chatter about query and batch performance last week, I
thought I would put in my experience.

Earlier we added a new 5094 to our 820 @ V5R3.  This hold 15 x 15KRPM
35GB drive on a 2780 controller.  We then halted and removed the 30
drive from our old Migration tower, (former 720 system unit.)  The 820
was performing a little better with the new drives.

Last night we upgraded the 820 /w 1100CPW to a 520 enterprise /w
3300CPW.  There was no OS or software changes made.  We moved the 12
drives and 2778 DASD controller from the 820 system unit to a 5095
tower. Interactive performance is great.  Queries appear to run slower.
Don't know about batch jobs yet.  

So to recap:
Old config was:
820 system unit - 1100 cpw
12 x 6718 drives on a 2778 DASD controller in system unit

Migration Tower ( former 720 system unit )
20 x 6717 and 10 x 6718 on two 2741 DASD controller
HSL1 loop from 820 to migration tower

Additional 5095 expansion tower with no drives attached via HSL1 to HSL2
cable

Then we added the 5094 tower with 2780 DASD controller and 15 x 4326
15KRPM 35GB disk drives.

We ran this was for 4 weeks waiting for our window to do the processor
upgrade with an increase of performance.

New Config is:
520 System unit - no drives

Migration tower - *Removed* (drive and all)
5095 tower - added 12 x 6718 drives on 2778 DASD controller

No change to 5094 tower as configured above

HSL loops all upgrade to latest HSL2 technology.

So we went from 42 DASD arms to 27 - replacing 30 old drive on 2 old
controllers with 15 new larger faster drive on the 2780 controller.

I think the reduction in arms and controller is NOT being made up by the
2780 and 15k RPM drives.

Chris Bipes 
Information Services Director
CrossCheck, Inc.