62 IBM ^ zSeries 990 Technical Guide
2.2.7 Model configurations
The z990 server model nomenclature is based on the number of PUs available for customer
use in each configuration. Four models of the z990 server are available:
IBM 2084 model A08: Eight PUs are available for characterization as CPs, IFLs, ICFs,
zAAPs (up to four), or additional SAPs.
IBM 2084 model B16: 16 PUs are available for characterization as CPs, IFLs, ICFs, zAAPs
(up to eight), or additional SAPs.
IBM 2084 model C24: 24 PUs are available for characterization as CPs, IFLs, ICFs,
zAAPs (up to 12), or additional SAPs.
IBM 2084 model D32: 32 PUs are available for characterization as CPs, IFLs, ICFs,
zAAPs (up to 16), or additional SAPs.
When a z990 order is configured, PUs are selected according to their intended usage. They
can be ordered as:
CP The Processor Unit purchased and activated supporting the z/OS,
OS/390, z/VSE, VSE/ESA, z/VM, and Linux operating systems, which
can also run the Coupling Facility Control Code (CFCC).
Unassigned CP A Central Processor purchased for future use as a CP. It is offline and
unavailable for use.
IFL The Integrated Facility for Linux (IFL) is a Processor Unit that is
purchased and activated for exclusive use by the z/VM and Linux
Unassigned IFL A Processor Unit purchased for future use as an IFL. It is offline and
unavailable for use.
ICF A Processor Unit purchased and activated for exclusive use by the
Coupling Facility Control Code (CFCC).
zAAP A Processor Unit purchased and activated for exclusive use to run
Java code under control of z/OS JVM.
Additional SAP The Optional System Assist Processor (SAP) is a Processor Unit that
is purchased and activated for use as a SAP.
Unassigned CPs are purchased PUs with the intention to be used as CPs, and usually have
this status for software charging reasons. Unassigned CPs do not count in establishing the
MSU value to be used for MLC software charging, or when charged on a per Processor Unit
Unassigned IFLs are purchased IFLs with the intention to be used as IFLs, and usually have
this status for software charging reasons. Unassigned IFLs do not count in establishing the
charge for either z/VM or Linux.
This method prevents RPQ handling in case a temporary downgrade is required. When the
capacity need arises, the unassigned CPs and IFLs can be assigned nondisruptively.
Concurrent CP, IFL, ICF, or zAAP upgrades are done within a z990 model. Concurrent
upgrades require PU spares. PU spares are PUs that are
not the two standard spares on
each MCM and are not characterized as a CP, IFL, ICF, zAAP, or SAP.
Chapter 2. System structure and design 63
If the upgrade request cannot be accomplished within the given model, a model upgrade is
required. A model upgrade will cause the addition of one or more books to accommodate the
desired capacity. Additional books can be installed concurrently.
Upgrades from one IBM 2084 model to another are concurrent and mean that one or more
books are added. Table 2-5 shows the possible model upgrades within the IBM 2084 model
Table 2-5 z990 upgrade paths
Upgrade paths from IBM 2064 models (z900) offer a virtually unrestricted upgrade capability.
Upgrades from any z900 to any z990 server are supported (with the exception of the IBM
2064 model 100, which can only can be upgraded to another z900 model).There are also no
upgrade paths from IBM 9672 G5 and G6 models, nor is there an upgrade path from the IBM
2066 models (z800).
There are limited upgrade paths from the 2086-A04 model (z890) to the 2084-A08 model
(z990). For details, contact your IBM representative or IBM Business Partner.
Figure 2-17 shows all upgrade paths from z900 to z990 models, and all upgrade paths within
the z990 model range.
Figure 2-17 Supported z900-to-z990 upgrade paths
In order to recognize how many PUs are characterized as a CP, the STSI instruction returns a
value that can be seen as a software model number to determine the number of assigned
CPs. Characterization of a PU as an IFL, an ICF, or an zAAP is not reflected in the output of
the STSI instruction, since they have no effect on MLC software charging.
z990 Models 2084-A08 2084-B16 2084-C24 2084-D32
2084-A08 - X X X
2084-B16 - - X X
2084-C24 - - - X