IBM Systems Magazine, Mainframe Edition - March/April 2013 - 18

IT Today
Quite often, the threads of
work that need to be done exceed
the available hardware resources
to run them in parallel. When this
happens, threads will be “stacked” on
the available resources and must wait
their turn to run. The extent to which
this happens on a machine for a given
workload is its stacking aspect.
Mainframe workloads are often
heavily stacked; that is, many threads
of work share the machine’s resources.
Other platforms come from a heritage
of a single workload per machine and
traditionally their workloads exploit the
threading aspect of machine capacity.
Unless the workload has low
variability resulting in sustained periods
of maximum use of the available or
required resources, threading will lead
to lower utilization of resources than
stacking. Virtualization and running
multiple workloads in an OS image to
increase utilization efficiency are, by
definition, stacking.
When dealing with virtual
machines (VMs) or LPARs, a further
suitability determination can be made
by examining how many virtual CPUs
the LPAR has threading; also, how the
local usage pattern will enable stacking
with the workload already on the
System z server. Generally, small VMs
become automatic candidates from a
workload perspective and large VMs
need to be examined for fit. Note that
most of the time this has nothing to
do with whether the workload is doing
I/O, running a particular language
or using a particular middleware. All
that matters—at least at this level of
discussion—is that the usage pattern
and service level requirement let us
stack the work.
To sum up, if it stacks, it’s a
candidate. System z can stack more
than 20 VMs per core. If a workload
doesn’t stack, it belongs on some form
of distributed processing.

18

MARCH/APRIL 2013

scalable 32-socket machines. The Intel
optimization limits the scaling for
machines of this size. Because of this,
any Intel workload that’s not efficiently
using many threads by clustering
compute nodes (highly threaded
and limited stacking) is potentially a
candidate for System z.

The fast threads
and large caches
on System z make
it well suited for
deeply stacked
work, particularly,
when the number
of loads contained
and their response
times are the
critical metrics.

Thread Speed and Cache
Fundamentally, a machine can either
have high-threading or high-stacking
resources—but not both. Threading
requires multiple cores per socket
(multicore) and multiple threads per core
(simultaneous multithreading). Stacking
requires thread speed and a good cache/
thread ratio. To provide a large number
of threads, Power* and Intel* servers
give up cache and thread speed. To
deliver greater cache and thread speed,
System z servers give up threads.
Intel also gives up scaling for
cost. It optimizes for smaller, two- to
four-socket machines. System z and
enterprise Power platforms build

ibmsystemsmag.com/mainframe

ITR and ETR
Standard benchmarks and common
capacity metrics—called internal
throughput rate (ITR) measurements—
are unsuitable for understanding
whether a workload fits on System z.
That’s because they’re based almost
entirely on the threading rather than
stacking aspect for workload. External
throughput rate (ETR) is what the client
experiences. ETR equates to ITR/
utilization. In many real workloads,
utilization varies significantly over short
periods of time. The usage pattern can
have more leverage on workload fit than
the ITR ratio.
The latest models of relative
capacity rely on fundamental design
and workload parameters, with a
case-specific ITR ratio as just one of
the considerations. Usage patterns and
service levels are at least as important as
benchmarked ITR, particularly when
stacking many small workloads into a
consolidated infrastructure.
The real metric of interest is
the cost per unit of work. Acceptable
response times per user or per
application instance are the applicable
performance metrics. This can be
expressed as the number of workload
instances contained per core with
reasonable service levels.
Infrastructure Architecture
The cost per unit of work is affected
by the infrastructure architecture,
which comes in two major forms. The
first is to build an infrastructure that


http://www.ibmsystemsmag.com/mainframe

IBM Systems Magazine, Mainframe Edition - March/April 2013

Table of Contents for the Digital Edition of IBM Systems Magazine, Mainframe Edition - March/April 2013

Table of Contents
Editor's Desk: Virtual Argument Over Cloud
IBM Perspective: The Perfect IT Combination
Data Display: IBM Mainframe: A Leader in Energy Efficiency
Trends: Batch Modernization Redefines Application Development
IT Today: Running Highly Stacked Workloads on System z Can Greatly Reduce Cost Per Unit of Work
Cover Story: Breaking Through Complexity: IBM Entry Cloud Configuration for SAP Solutions bring simplicity and efficiency
Feature: Reach Cloud's Potential: Build your IT environment with IBM zEnterprise and SmartCloud
Tech Corner: System z Virtualization Environment Provides Far Lower TCA Than Its Intel Alternative
Solutions: CA Database Management Solutions for DB2 for z/OS, and CA Mainframe Chorus; Attachmate Reflection 2011 R3; PerfTechPro for z/OS; Compuware APM for Mainframe
Advertisers Index
Stop Run
Reference Point - Global Events, Education, Resources for Mainframe
Special Report: Mobile Mainframe
2013 Mainframe Buyer's Guide Index
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Intro
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Cover1
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Cover2
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 1
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Table of Contents
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 3
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 4
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 5
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Editor's Desk: Virtual Argument Over Cloud
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 7
IBM Systems Magazine, Mainframe Edition - March/April 2013 - IBM Perspective: The Perfect IT Combination
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 9
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Data Display: IBM Mainframe: A Leader in Energy Efficiency
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 11
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Trends: Batch Modernization Redefines Application Development
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 13
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 14
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 15
IBM Systems Magazine, Mainframe Edition - March/April 2013 - IT Today: Running Highly Stacked Workloads on System z Can Greatly Reduce Cost Per Unit of Work
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 17
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 18
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 19
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Cover Story: Breaking Through Complexity: IBM Entry Cloud Configuration for SAP Solutions bring simplicity and efficiency
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 21
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 22
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 23
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 24
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 25
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Feature: Reach Cloud's Potential: Build your IT environment with IBM zEnterprise and SmartCloud
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 27
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 28
IBM Systems Magazine, Mainframe Edition - March/April 2013 - BB1
IBM Systems Magazine, Mainframe Edition - March/April 2013 - BB2
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 29
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 30
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 31
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Tech Corner: System z Virtualization Environment Provides Far Lower TCA Than Its Intel Alternative
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 33
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 34
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 35
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 36
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 37
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Solutions: CA Database Management Solutions for DB2 for z/OS, and CA Mainframe Chorus; Attachmate Reflection 2011 R3; PerfTechPro for z/OS; Compuware APM for Mainframe
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Advertisers Index
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Stop Run
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Cover3
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Cover4
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Reference Point - Global Events, Education, Resources for Mainframe
IBM Systems Magazine, Mainframe Edition - March/April 2013 - RF2
IBM Systems Magazine, Mainframe Edition - March/April 2013 - Special Report: Mobile Mainframe
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS2
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS3
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS4
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS5
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS6
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS7
IBM Systems Magazine, Mainframe Edition - March/April 2013 - MS8
IBM Systems Magazine, Mainframe Edition - March/April 2013 - 2013 Mainframe Buyer's Guide Index
IBM Systems Magazine, Mainframe Edition - March/April 2013 - BG2
IBM Systems Magazine, Mainframe Edition - March/April 2013 - BG3
http://www.ibmsystemsmagmainframedigital.com/mspcomm/ibmsystemsmag/ibmsystems_mainframe_20200708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20200506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20200304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20200102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/2020mfse
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20191112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20190910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20190708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20190506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20190304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/relevantz_20190102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/2019mfse
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20190102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20181112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20180910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20180708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20180506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20180304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20180102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/2018mfse
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20171112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170910_v2
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_sesupp
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20170102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_linuxsupp
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20161112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/MainframeSecurity
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20160910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20160708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20160506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20160304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20160102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20151112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150910_se
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150910
http://www.ibmsystemsmagmainframedigital.com/MFSkills
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150506_supp
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20150102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20141112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140910_v2
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_gt_201405
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/BigData
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20140102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20131112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130910_v2
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20130102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20121112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/buyersguide2013
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20120910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20120708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20120506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20120304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20120102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/ibmsystems_mainframe_2012bg
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20111112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20110910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20110708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20110506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20110304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20110102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20101112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100910_bg
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100506
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100304
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20100102
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20091112
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20090910
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20090708
http://www.ibmsystemsmagmainframedigital.com/nxtbooks/ibmsystemsmag/mainframe_20090506
https://www.nxtbook.com/nxtbooks/ibmsystemsmag/mainframe_20090304
https://www.nxtbookmedia.com