IBM 990 - Manual (Page 237)

Chapter 8. Capacity upgrades 225
determine the capacity of processor B relative to that of processor A, the ITR Ratio (ITRR) is
calculated as follows:
ITRR = ITR for Processor B / ITR for Processor A
ITR values used in this calculation must be for identical workloads environments.
Each individual LSPR workload is designed to focus on a single major type of activity, such
as interactive, online database, or batch. The LSPR does not focus on individual pieces of
work, such as a specific job or application. Instead, each LSPR workload includes a broad
mix of activity related to that workload type.
The ITR value for each workload environment is measured for IBM (and some non-IBM)
processors and the results are published via LSPR tables. An LSPR table shows the ITR
Ratios (ITRRs) of each processor within a group related to a base processor. The base
processor is set as ITR = 1 for all workloads, so all other processors in the table are
compared to the base one, for each workload environment.
To obtain a single number that could estimate the average capacity of a given processor, a
mixed workload is also calculated. A mixed workload consists of a mix of selected LSPR
workloads. Remember that single-number capacity tables may be useful for rough processor
positioning, but cannot provide a precise view of relative processor capacity and should not
be used for capacity planing purposes.
The LSPR is now using new predefined mixed workloads, offering better average capacity
estimation for the most usual production environments, and providing more representative
average numbers for relative processor capacity evaluation.
LSPR workloads prior to z990
The LSPR workloads prior to z990 are listed Table 8-2. The measured ITRs represent Basic
Mode.
Table 8-2 LSPR workloads prior to z990 (Basic Mode)
The default mixed workload consists of an equal mix (25%) of CB84, TSO, CICS/DB2, and
IMS workloads, running under OS/390 V2 R10 in Basic mode, in a mixture of 31-bit and 64-bit
mode addressing.
Operating system Workload type Workload description
OS/390 FCP1 Engineering and Scientific batch (Floating Point)
CBW2 CPU-intensive commercial batch
CB84 I/O-intensive commercial batch
TSO Interactive TSO user population
CICS/DB2 Traditional OLTP using CICS and DB2
IMS Traditional OLTP using IMS
R3-DB EAS DB server (SAP SD benchmark)
VM/ESA CMS1 Interactive CMS user population
VSE/ESA CICS Traditional OLTP using CICS
CICS VM/V=R Traditional OLTP using CICS as a VM V=R guest