I/O Connectivity

New design for increased performance: FICON Express8S contains a new IBM ASIC which is designed to support the 8 GBps PCIe interface to the PCIe I/O drawer and increased start I/Os. In addition, a hardware data router has been added in support of the zHPF and FCP protocols for path length reduction and increased throughput. FICON Express8S supports a link data rate of 2, 4, or 8 Gbps autonegotiated.

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The High Performance FICON for System z journey:

• In October of 2008 we made the initial zHPF announcement on System z10 with FICON Express4 and FICON Express2 channels
  • Maximum of 31k zHPF IOs/sec, 2.2 times the FICON protocol,
  • Single track limit for zHPF data transfers
• In July 2009 we introduced FICON Express8 channels on System z10
  • Maximum of 52k zHPF IOs/sec
  • 64k byte limit for zHPF data transfers
• In July 2010 we introduced additional support on zEnterprise 196
  • Extension to multi-tracks of zHPF data transfers
• In July 2011 with the new FICON Express8S channel on zEnterprise 196 and zEnterprise 114
  • A hardware data router is introduced for more efficient zHPF data transfers.
  • FICON Express8S channel is the first channel with hardware specifically designed to support zHPF. FICON Express8, FICON Express4, and FICON Express2 have a firmware-only zHPF implementation.

In laboratory measurements, using FICON Express8S in a z196 with the zHPF protocol and small data transfer I/O operations, FICON Express8S operating at 8 Gbps achieved a maximum of 92,000 IOs/sec, compared to the maximum of 52,000 IOs/sec achieved with FICON Express8 operating at 8 Gbps. This represents approximately a 77% increase and applies to reads, writes, and a read/write mix.

In laboratory measurements, using FICON Express8S in a z196 with the zHPF protocol and a mix of large sequential read and write data transfer I/O operations, FICON Express8S operating at 8 Gbps achieved a maximum throughput of 1600 MB/sec (reads + writes) compared to a maximum of 770 MB/sec (reads + writes) achieved with FICON Express8 operating at 8 Gbps. This represents approximately a 108% increase.

This performance data was measured in a controlled environment running an I/O driver program under z/OS. The actual throughput or performance that any user will experience will vary depending upon considerations such as the amount of multiprogramming in the user's job stream, the I/O configuration, the storage configuration, and the workload processed.