IBM 990 Manuel D’Utilisation

Chapter 3. I/O system structure 

Draft Document for Review April 7, 2004 6:15 pm

The z990 FICON Express SX feature (feature code 2320) occupies one I/O slot in the z990 
I/O cage. The feature has two Peripheral Component Interconnect cards. Each PCI card has 
a single port supporting an LC Duplex connector, with one PCHID associated with each port, 
and supports link speeds of 1Gbps and 2 Gbps.

Each port supports attachment to the following:

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Fibre Channel Switch that supports 1Gbps/2Gbps Fibre Channel/FICON SX

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Control unit that supports 1Gbps/2Gbps Fibre Channel/FICON SX

Each port of the z990 FICON Express SX feature uses an 850 nanometer (nm) fiber 
bandwidth transceiver. The port supports connection to a 62.5 micron or 50 micron multimode 
fiber optic cable terminated with an LC Duplex connector.

When configured for FCP mode, the FICON Express features can access FCP devices either: 

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Via a FICON channel in FCP mode through a single Fibre Channel switch or multiple 
switches to an FCP device

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Via a FICON channel in FCP mode through a single Fibre Channel switch or multiple 
switches to a Fibre Channel-to-SCSI bridge

The z990 servers, Linux for zSeries, and z/VM work together to provide performance 
improvements by exploiting extensions to the Queued Direct Input/Output (QDIO) 
architecture. Adapter Interruptions, first added to z/Architecture with HiperSockets, provide an 
efficient, high-performance technique for I/O interruptions to reduce path lengths and 
overhead in both the host operating system and the adapter - FICON Express, when using 
the FCP CHPID type.

In extending the use of adapter interruptions to FCP channels, the programming overhead to 
process a traditional I/O interruption is reduced. This benefits FCP support in Linux for 
zSeries.

Note: Mode Conditioning Patch (MCP) cables are for use with 1 Gbit/sec (100 MB/sec) 
links 

.

Multimode (62.5 or 50 micron) fiber optic cable may be used with the z990 FICON Express 
LX feature for 1 Gbps 

. The use of this multimode cable type requires a Mode 

Conditioning Patch (MCP) cable to be used at each end of the fiber optic link, or at each 
optical port in the link. Use of the single-mode to multimode MCP cables reduces the 
supported optical distance of the 1 Gbps link to an end-to-end maximum of 550 meters.

Fiber optic conversion kits and Mode Conditioning Patch (MCP) cables are not 
orderable as features on z990. Fiber optic cables, cable planning, labeling, and 
installation are all customer responsibilities for new z990 installations and upgrades.

IBM Fiber Cabling Services offer total a cable solution service to help with your cable 
ordering needs, and is highly recommended.

Note: z990 FCP channel direct attachment in point-to-point and arbitrated loop topologies 
is not supported as part of the zSeries FCP enablement.