IBM 990 - Manual (Page 75)

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
range.
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
Software models
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
2084-D32 - - - -
z900 z990
100
101-109
1C1-116
2C1-216
A08
B16
C24
D32