Designed 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.
The High Performance FICON for IBM z Systems journey:
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. Results on zEC12 and zBC12 are comparable.
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. Results on zEC12 and zBC12 are comparable.
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.
For information about the Channel subsystem enhancement for I/O resilience, SAP capacity performance improvements, and performance characteristics of the FICON Express8S channels on the zEnterprise EC12 refer to: IBM zEC12 IO performance technical paper (PDF, 235KB).
I/O priority manager is a function which can help enable greater cache efficiency and improve performance for higher priority workloads residing on IBM System Storage DS8000. To understand more, refer to this paper: IBM z Systems DS8000 I/O Priority Manager (PDF, 908KB).
To understand the I/O performance characteristics of the FICON Express8S channels, refer to Version 2 of the "IBM zEnterprise 196 and IBM zEnterprise 114 I/O and FICON Express8S Channel Performance paper" (PDF, 523KB). This update (Version 2) includes information on High Performance FICON for z Systems (zHPF) enhancements for QSAM, BPAM, and BSAM access methods, for format writes, and for improvements in DB2 list prefetch for certain DB2 queries and some DB2 utility operations.
To understand the I/O performance characteristics of the IBM zEnterprise™ 196 as well as the extensions to High Performance FICON for IBM z Systems® (zHPF) architecture available on FICON® Express8 and FICON Express4 channels refer to IBM zEnterprise 196 I/O Performance Version 1 (PDF, 280KB) technical paper.
For detailed performance information on FICON Express8 on System z10, refer to IBM System z10 FICON Express8 Channel Performance Version 1 (PDF, 192KB) technical paper.
For detailed information on High Performance FICON on z Systems (zHPF) using FICON Express4 and FICON Express2 on System z10 to provide optimization for OLTP workloads, refer to IBM System z10 I/O and High Performance FICON for z Systems Channel Performance (PDF, 248KB) technical paper.