Mainframes, MVS, zOS and Related Languages Support Forums Help & Support Forum for and by Mainframe Users 2013-08-19T09:43:15+00:00 2013-08-19T09:43:15+00:00 2013-08-19T09:43:15+00:00 <![CDATA[Off-Topics, FAQs. • Re: MSU and MIPS]]>

On second thoughts, can we merge the both the topics? I should have searched the forum.
That's fine Quasar, no problem with that. I referred the other topic just in case that gives you better insight.

Have a good one,

Statistics: Posted by Anuj Dhawan — Mon Aug 19, 2013 9:43 am

2013-08-18T16:59:23+00:00 2013-08-18T16:59:23+00:00 <![CDATA[Off-Topics, FAQs. • Re: MSU and MIPS]]>
I read the article quoted by you. CPU time can be converted to SUs by multiplying DURATION x SU_SEC(the SU_SEC is processor dependent). SU_SEC differs, because different processors have different clock speeds, so one z12 CPU second is not equal to one z10 CPU second.

MSU capacity of an LPAR would be = SU's x 60 x 60 x ENGINES. To add to it, Robert said, some SU's of the second engine are spent in co-ordination. MXG, Omegamon and several other products can tell you the MSU capacity of you

There are other interesting things I came across like "Technology Dividend". IBM offers a 10% MSU discount, when you upgrade to a newer generation of System Z. If work is done on specialty engines like zIIP and zAAP, MSU capacity is affected.


Thanks for the excellent example!

On second thoughts, can we merge the both the topics? I should have searched the forum.


Statistics: Posted by Quasar Chunawala — Sun Aug 18, 2013 4:59 pm

2013-08-18T11:35:51+00:00 2013-08-18T11:35:51+00:00 <![CDATA[Off-Topics, FAQs. • Re: MSU and MIPS]]>
MSU is short for Millions of Service Units (since most capacity planning is looking at usage by hour, not by second, multiply SU_SEC times 60 times 60 to derive MSU).

Statistics: Posted by Robert Sample — Sun Aug 18, 2013 11:35 am

2013-08-18T08:14:08+00:00 2013-08-18T08:14:08+00:00 <![CDATA[Off-Topics, FAQs. • Re: MSU and MIPS]]> On other topic of similar nature I was talking to Robert - adding your question to that leads us into something that appears to cause great confusion and interesting too at the same time – just what are MSU and what do they mean? But that we might continue there too.

OTOH, SU_SEC comes from R723MADJ in the SMF TYPE72 records, and is specific to the system being IPLed and so is constant for that machine but changes as the m/c changes. This is from an online found resource:


The fact that some TYPE72 reporting is in service units raises the question of how time is converted to service units and, how we can convert back from service units to time. Since it seems obvious that the total capacity we have on our machine in any given interval is the duration of that interval times the number of processors we have, CAPACITY=DURATION*ENGINES, how do we convert from service units to time and see how much capacity we actually used in a given amount of time? IBM’s answer is the R723MADJ field, which gives us the service units per second, expressed in Merrill Consultants MXG product as SU_SEC. The term SU_SEC will be used through the rest of this paper to refer to the value of service units per second given to us in the TYPE72 data. The way this value is determined is of extreme interest to us as capacity planners.

The SU_SEC is determined at IPL time and is based on the number of engines online to an LPAR at IPL time. The IBM SRM constants table is in memory. The STSI model number corresponding to the number of engines for the STIDP processor type is determined and that value is reported by the TYPE72s for the life of the IPL. An example is if the processor is a 2094 and there are six engines online at IPL, then the SU_SEC will be the SRM constant for a 2094-706. Before IRD, this was no problem. The number of processors online to an LPAR remained constant unless changed by manual intervention, something rarely done in most shops. After IRD became available, the machine makes changes automatically and no one really knows how many engines are online to an LPAR during a given interval. A good guess can be made by sampling, and RMF does this. But, the amount of actual time consumed by each service or report class cannot be determined any more with true reliability. And keep in mind that when more engines are online the fewer service units any one engine can actually deliver. Conversely, when fewer engines are online, the more service units each one can deliver.

Statistics: Posted by Anuj Dhawan — Sun Aug 18, 2013 8:14 am

2013-08-18T05:55:53+00:00 2013-08-18T05:55:53+00:00 <![CDATA[Off-Topics, FAQs. • MSU and MIPS]]>
MIPS has never been used as a unit to measure mainframe processing power. Instead, they use SU(Service units). A simple equation one could formulate to calculate capacity would be,

Capacity(MSU's) = Duration x SU_SEC(constant published by IBM).

I do not understand, why the SU_SEC constant different for various models of System Z?


Statistics: Posted by Quasar Chunawala — Sun Aug 18, 2013 5:55 am

2013-08-11T05:57:41+00:00 2013-08-11T05:57:41+00:00 <![CDATA[Off-Topics, FAQs. • How often do you switch off your computer monitor when not..]]> Statistics: Posted by Anuj Dhawan — Sun Aug 11, 2013 5:57 am

2013-07-31T05:47:40+00:00 2013-07-31T05:47:40+00:00 <![CDATA[Off-Topics, FAQs. • Re: Why aren't young programmers interested in mainframes?]]> Statistics: Posted by Anuj Dhawan — Wed Jul 31, 2013 5:47 am

2013-07-27T17:55:21+00:00 2013-07-27T17:55:21+00:00 <![CDATA[Off-Topics, FAQs. • Re: Why aren't young programmers interested in mainframes?]]>
If anyone was interested in the 'New Technology' of the day it was either Mainframe or nothing!

Maybe with the ease of being able to access machines thousands of times more powerful and small enough to fit in your hand these days, young programmers don't see the need to study what they see as immobile, and outdated hardware?

Of course we all know that's nonsense, however most youngsters these days seem to be preoccupied with getting the smallest, fastest and most powerful device possible. Generally seeming to overlook or ignore the enormous power and potential of a modern Mainframe.

Just my thoughts on the subject.

Statistics: Posted by Darklord — Sat Jul 27, 2013 5:55 pm

2013-07-27T10:57:10+00:00 2013-07-27T10:57:10+00:00 <![CDATA[Off-Topics, FAQs. • Re: What is FOUCS and where can I find books on it?]]>

Statistics: Posted by AD991 — Sat Jul 27, 2013 10:57 am

2013-07-26T12:53:02+00:00 2013-07-26T12:53:02+00:00 <![CDATA[Off-Topics, FAQs. • Re: We made a Century!!]]> Making Century is a history now -- We made Much More than a Double Century!

Most users ever online was 250 on 26 Jul 2013
script 01:01

What are you waiting for -- come get along with this busy community to clear, debate and discuss your doubts on IBM Mainframes, MVS, zOS and related Languages.

Statistics: Posted by Anuj Dhawan — Fri Jul 26, 2013 12:53 pm

2013-07-26T04:48:11+00:00 2013-07-26T04:48:11+00:00 <![CDATA[Off-Topics, FAQs. • "Report This Post" is activated.]]>
The "Report This Post Button" can be found as the first button with exclamation sign ("!"), at bottom right of any post. The pictorial representation is shown below:

Statistics: Posted by Anuj Dhawan — Fri Jul 26, 2013 4:48 am

2013-07-23T06:55:33+00:00 2013-07-23T06:55:33+00:00 <![CDATA[Off-Topics, FAQs. • Re: How regularly do you follow a fitness regimen?]]>

Statistics: Posted by Angel — Tue Jul 23, 2013 6:55 am

2013-07-23T06:20:50+00:00 2013-07-23T06:20:50+00:00 <![CDATA[Off-Topics, FAQs. • Re: What is MIPS, are we being misled By the Term "MIPS"?]]>

Statistics: Posted by Anuj Dhawan — Tue Jul 23, 2013 6:20 am

2013-07-23T06:19:28+00:00 2013-07-23T06:19:28+00:00 <![CDATA[Off-Topics, FAQs. • Re: What is MIPS, are we being misled By the Term "MIPS"?]]> as another (RISC vs. CISC (As Andy Grove mentions about it in "... Paranoid Survive"), mainframe vs. PC). As a result, MIPS has been called with many alternative names, which are mentioned before.

Again - MIPS measures roughly the number of machine instructions that a computer can execute in one second. However, different instructions require more or less time than others, and there is no standard method for measuring MIPS. In addition, MIPS refers only to the CPU speed, whereas real applications are generally limited by other factors, such as I/O speed. A machine with a high MIPS rating, therefore, might not run a particular application any faster than a machine with a low MIPS rating. And all these reasons are enough for not to sue MIPS ratings anymore for this very purpose. Perhaps now it's just a 'Meaningless Indicator of Performance'.

Statistics: Posted by Anuj Dhawan — Tue Jul 23, 2013 6:19 am

2013-07-19T19:11:01+00:00 2013-07-19T19:11:01+00:00 <![CDATA[Off-Topics, FAQs. • Re: We made a Century!!]]>
Today it is 165!!!

Statistics: Posted by Anuj Dhawan — Fri Jul 19, 2013 7:11 pm

2013-07-19T06:55:56+00:00 2013-07-19T06:55:56+00:00 <![CDATA[Off-Topics, FAQs. • Re: Don't Be Misled By MIPS.]]> Statistics: Posted by Sachin Kumar — Fri Jul 19, 2013 6:55 am

2013-07-18T11:18:39+00:00 2013-07-18T11:18:39+00:00 <![CDATA[Off-Topics, FAQs. • Re: Don't Be Misled By MIPS.]]>
I've seen people refer to an application using so many MIPS. No, it does not -- unless an entire machine (LPAR) is dedicated to that application. It may use so many CPU seconds, or so many I/O, or so much memory -- but it does not use MIPS (or MSU).

Statistics: Posted by Robert Sample — Thu Jul 18, 2013 11:18 am

2013-07-18T05:48:51+00:00 2013-07-18T05:48:51+00:00 <![CDATA[Off-Topics, FAQs. • What is MIPS, are we being misled By the Term "MIPS"?]]>
  • Misleading indicator of processor speed
  • Managements impression of processor speed
  • Meaningless indicator of processor speed

and probably many more.

Well, jokes apart but it's none of them. In a crude sense, MIPS is a "through put" of a system and one, in the Business and working with IBM Products, must understand that IBM has stopped using this term long back and using "MSU" instead.

I'd request the members to please chip-in in this discussion to conclude on how logical is it to say "MIPS reduction in 2013", when one in the management suddenly starts talking about to find out a figure to represent a processor's capacity and in turn the "Software Engineers" starts spending large amounts of money based on a poorly understood indicator, for both software and hardware perspective.

There is lot more to talk about and I'll get back to this half completed topic soon - just now I'm getting a call for a Ticket in Production...:)

Be well,


Statistics: Posted by Anuj Dhawan — Thu Jul 18, 2013 5:48 am

2013-07-18T05:35:38+00:00 2013-07-18T05:35:38+00:00 <![CDATA[Off-Topics, FAQs. • We made a Century!!]]>

We got 121 users online Yesterday, on 17 Jul 2013 at 22:54. You can check that at the bottom of Board Index. This will be shown like this: "Most users ever online was 121 on 17 Jul 2013 22:54".

That's a great achievement.

Thanks for Liking and showing the trust in to the Labor we're putting in, much appreciate that,


Statistics: Posted by Anuj Dhawan — Thu Jul 18, 2013 5:35 am

2013-07-16T06:44:48+00:00 2013-07-16T06:44:48+00:00 <![CDATA[Off-Topics, FAQs. • Re: How regularly do you follow a fitness regimen?]]>

Statistics: Posted by Anuj Dhawan — Tue Jul 16, 2013 6:44 am