IBM 990 Reference Manual page 51

Processor Unit Assignments
Model Min. PU* Max. PU
A08** 1 8
B16** 1 16
C24** 1 24
D32** 1 32
*PU can be characterized as CP, IFL, ICF, Optional SAPs, unassigned
CPs, and/or unassigned IFLs up to a max number of PUs for the model
**Customer will be required to purchase at least one CP, IFL or ICF feature
for any model.
Processor Memory
z990 Model Minimum
A08
16 GB
B16 16 GB
C24
16 GB
D32 16 GB
Max two memory cards per z990 book. Memory cards 8 GB, 16 GB or 32
GB.
Channels
Model A08
ESCON Min 0
**ESCON Max 720
FICON *Min
0
FICON *Max 96
*FICON Express and FCP confi gured on the same FICON Express features.
Max channels total 120.
**ESCON increments of 4 channels
SAP Standard Spares Standard
2 2
4 4
6 6
8 8
Maximum
64 GB
128 GB
192 GB
256 GB
B16 C24 D32
0 0 0
1024 1024 1024
0 0 0
120 120 120
Coupling Links
Links IC ICB-2* ICB-3**
0-32 0-8 0-16
*requires STI-2 card
**requires STI-3 card
Note: At least one I/O channel (FICON, ESCON) or one coupling link (ISC,
ICB) must be present.
Cryptographic Features
Minimum
Maximum
1. Max two PCICA features per I/O cage
2. Max eight PCICA and PCIXCC features per system
3. Two accelerator cards per PCICA feature
4. One coprocessor per PCIXCC feature
OSA-Express Features
Minimum
Maximum
*Any combination of GbE LX, GbE SX, 1000BASE-T Ethernet, Token-Ring
51
ICB-4 ISC-3 Max Links
0-16 0-48 Total External
and Internal
links = 64
PCICA 1, 2 PCIXCC 2
0 0
6 3 4 4
OSA-Express* Features
0
24