6947ch03.fm Draft Document for Review April 7, 2004 6:15 pm
74 IBM eServer zSeries 990 Technical Guide
3.1 Overview
The z990 I/O system design provides great flexibility, high availability and performance,
allowing:
High bandwidth
The z990 I/O system can handle up to 96 GB/sec, which is four times the z900 server’s
bandwidth. Individual channels can have up to 2 Gb/sec and individual Coupling Facility links
up to 2 GB/sec data rates.
Wide connectivity
A z990 server can be connected to an extensive range of interfaces, using protocols such as
Fibre Channel Protocol (FCP) for Small Computer System Interface (SCSI), Gigabit Ethernet
(GbE), 1000BASE-T Ethernet, 100BASE-T Ethernet, 10BASE-T Ethernet, Token Ring along
with FICON Express, ESCON and coupling links channels.
Cryptographic functions
The z990 I/O system also supports optional cryptographic cards to complement the standard
CP Assist for Cryptographic Function (CPACF) that is implemented in every PU, enhancing
the performance of cryptographic processing.
Concurrent I/O upgrades
It is possible to concurrently add I/O cards to a z990 server provided there are unused slot
positions in an I/O cage. Additional I/O cages can be previously installed on an initial
configuration, via CUoD, to provide greater capacity for concurrent upgrades. This capability
may help eliminate an outage to upgrade the I/O configuration. See more information about
concurrent upgrades on Chapter 8, “Capacity upgrades” on page 185.
Dynamic I/O configuration
Dynamic I/O configuration enhances system availability by supporting the dynamic addition,
removal, or modification of channel paths, control units, I/O devices, and I/O configuration
definitions to both hardware and software (if it has this support) without requiring a planned
outage.
ESCON port sparing and upgrading
The ESCON 16-port I/O card includes one unused port dedicated for sparing in the event of a
port failure on that card. Other unused ports are available for growth of ESCON channels
without requiring new hardware, enabling concurrent upgrades via Licensed Internal Code
(LIC).
The following I/O feature
ports are supported in the zSeries 990 server:
Up to 1024 ESCON (up to 720 ESCON on model A08)
Up to 120 Fibre Connection (FICON) Express (up to 96 FICON on model A08)
Up to 48 Open Systems Adapter (OSA) Express
Up to 16 Integrated Cluster Bus-4 (ICB-4) (up to 12 ICB-4 on model A08)
Up to 16 Integrated Cluster Bus-3 (ICB-3)
Up to 8 Integrated Cluster Bus-2 (ICB-2)
Up to 48 Inter-System Channel-3 (ISC-3) in peer mode (up to 32 ISC-3 in compatibility
mode)
Up to 2 External Time Reference (ETR)
Note: The maximum number of Coupling Links combined (IC, ICB-2, ICB-3, ICB-4, and
active ISC-3 links) cannot exceed 64 per z990 server.
