According to '2008 No.4 Sheryl Watson's Tuning letter' the performance
benefit is expected the range of 0 to 10%. Our shop will have a 3-way
z10-BC, and three z/OS images are small enough fit in a book, and our
shop is heavily batch run will be falling at the low-end of the range.
The following lessens my confidence;
1) Why default is off, even if it's good enough to be a performance
escalation
2) The majority of installations that bring in a z10 are not turning on
3) Large installations are very afraid to "rock the boat". Anything
can affect
Production workload is guilty until proven innocent.
4) Applying two dozens of APARs is somewhat risky
John Kim
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On
Behalf Of Edward Jaffe
Sent: Monday, December 08, 2008 9:17 AM
To: [email protected]
Subject: Re: First z10 BC on West Coast
John Kim wrote:
> Ed,
>
> I wonder have you turned on 'HIPERDISPATCH=YES' and what the
performance
> looks like with this option?
>
Funny you mention that. Yesterday, I logged on and noticed the
following:
IEAVEH071E HiperDispatch is expected to be enabled but it is disabled
So, I added HIPERDISPATCH=YES to IEAOPTxx. Once I issued T OPT=xx, the
system(s) responded with:
N 0040000 MVSA0 08342 15:29:07.45 00000090 IRA860I
HIPERDISPATCH MODE IS NOW ACTIVE
Book affinity is obviously not important for a single-book machines. Of
course, so-called "short" CPs can exist on most n-way machines. Ours is
only a 4-way.
We'll try some empirical testing over the next few weeks to see if we
notice any change with HiperDispatch enabled or disabled.
> We are also going to have a z10-BC soon, but haven't decided yet to
turn
> on.
> Because lots of pros and cons out there. We have 3 LPARs; one
production
> and two tiny tests.
>
What kind of cons? Due to implementation "bugs" that have been found? Or
something more fundamental?
--
Edward E Jaffe
Phoenix Software International, Inc
5200 W Century Blvd, Suite 800
Los Angeles, CA 90045
310-338-0400 x318
[EMAIL PROTECTED]
http://www.phoenixsoftware.com/
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