IBM manual Z10 BC Performance, Large System Performance Reference, CPU Measurement Facility

z10 BC Performance

The performance design of the z/Architecture can enable the server to support a new standard of performance for applications through expanding upon a balanced system approach. As CMOS technology has been enhanced to support not only additional processing power, but also more PUs, the entire server is modifi ed to support the increase in processing power. The I/O subsystem supports a greater amount of bandwidth than previous generations through internal changes, providing for larger and faster volume of data movement into and out of the server. Sup- port of larger amounts of data within the server required improved management of storage confi gurations, made available through integration of the operating system and hardware support of 64-bit addressing. The combined bal- anced system design allows for increases in performance across a broad spectrum of work.

Large System Performance Reference

IBM’s Large Systems Performance Reference (LSPR) method is designed to provide comprehensive z/Architecture processor capacity ratios for different con-

figurations of Central Processors (CPs) across a wide variety of system control programs and workload envi- ronments. For z10 BC, z/Architecture processor capacity identifi er is defi ned with a (A0x-Z0x) notation, where x is the number of installed CPs, from one to fi ve. There are a total of 26 subcapacity levels, designated by the letters A through Z.

In addition to the general information provided for z/OS V1.9, the LSPR also contains performance relationships for z/VM and Linux operating environments.

Based on using an LSPR mixed workload, the perfor- mance of the z10 BC (2098) Z01 is expected to be:

• up to 1.4 times that of the z9 BC (2096) Z01.

Moving from a System z9 partition to an equivalently sized System z10 BC partition, a z/VM workload will experience an ITR ratio that is somewhat related to the workload’s instruction mix, MP factor, and level of storage over com- mitment. Workloads with higher levels of storage over commitment or higher MP factors are likely to experience lower than average z10 BC to z9 ITR scaling ratios. The range of likely ITR ratios is wider than the range has been for previous processor migrations.

The LSPR contains the Internal Throughput Rate Ratios (ITRRs) for the z10 BC and the previous-generation zSeries processor families based upon measurements and projections using standard IBM benchmarks in a con- trolled environment. The actual throughput that any user may experience will vary depending upon considerations such as the amount of multiprogramming in the user’s job stream, the I/O confi guration, and the workload processed. Therefore no assurance can be given that an individual user will achieve throughput improvements equivalent

to the performance ratios stated. For more detailed per- formance information, consult the Large Systems Perfor- mance Reference (LSPR) available at: http://www.ibm.com/servers/eserver/zseries/lspr/.

CPU Measurement Facility

The CPU Measurement Facility is a hardware facility which consists of counters and samples. The facility provides a means to collect run-time data for software performance tuning. The detailed architecture information for this facility can be found in the System z10 Library in Resource Link™.

17