Jake if you are looking to do this yourself then there are two different web
pages from IBM that might help you.
My suggestion would be to take a look at the information related to these
web pages. IBM explains how it came up with this information.
Using the example from Jay here is what those web pages show for the
z14-L02 compared to the z16-M02.
Processor STIDP Type STSI Model #CP SU/SEC
SRMsec/RealSec
3907-L02 3907 L02 2 16343.2074 404.5305
3932-M02 3932 M02 2 17758.0466 433.6749
Processor version codes and SRM constants
<https://www.ibm.com/support/pages/processor-version-codes-and-srm-constants
>
Processor #CP PCI** MSU*** Low* Average* High*
3907-L02 2 639 80 1.21 1.14 1.04
3932-M02 2 693 87 1.28 1.24 1.16
IBM Z Large Systems Performance Reference
<https://www.ibm.com/support/pages/ibm-z-large-systems-performance-reference
>
Paul
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of
Phil Smith III
Sent: Friday, June 12, 2026 09:58 AM
To: [email protected]
Subject: Re: Selecting z model MSU
In theory, MSUs are the right answer, because they're supposed to be
normalized reflections of real-world throughput. OTOH there's the
"technology dividend", where a new machine's MSUs may be "larger" than the
previous machine's--IOW, n MSUs on a newer machine may net you better
performance than the same n MSUs on an older machine. (Or maybe this is just
because the old machine is getting rusty :) )
And of course there's the fact that different workloads perform
differently.
But MIPS are even fuzzier and are thus a worse measure.
In theory, there are IBM sales reps who should be able to help with this,
too.
-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]
<mailto:[email protected]> > On Behalf Of Jay Maynard
Sent: Friday, June 12, 2026 10:51 AM
To: [email protected] <mailto:[email protected]>
Subject: Re: Selecting z model MSU
When we did this last year, we simply picked the capacity level that was
the closest match to the z14's and wasn't any smaller. We wound up going
from a z14-L02 to a z16-M02. It's worked out well for us.
On Fri, Jun 12, 2026 at 8:27 AM Jake Anderson <
[email protected]
<mailto:[email protected]> > wrote:
> Hello
>
> Are there any specific headroom for MSU to be considered while moving
> from
> z14 to z16
>
> For example ,
> If we have 55MSU, What would be the formula or a best approach to
> select a
> z16 ?
>
> Considering based on MIPS is a good idea or an MSU ?
>
> Any pointers would be appreciated
>
> Regards
> Jake
>
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--
Jay Maynard
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