13 performance – IBM 990 User Manual
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Chapter 1. zSeries 990 overview
17
1.3.13 Performance
The IBM Large Systems Performance Reference method provides comprehensive
z/Architecture processor capacity data for different configurations of central processing units
across a wide variety of system control program and workload environments. For zSeries
z990, z/Architecture processor capacity is defined with a 3xx notation, where xx is the number
of installed Central Processor (CP) units.
The actual throughput 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, and
the workload processed. Therefore, no assurance can be given that an individual user will
achieve throughput improvements equivalent to the performance ratios shown in Figure 1-5.
For more detailed performance information, consult the Large Systems Performance
Reference (LSPR), found at:
Figure 1-5 Performance comparison, SW models, and HW models
MSU values for all z990 software models are found at:
1.3.14 Reliability, Availability, and Serviceability (RAS)
The z990 RAS strategy is a building-block approach developed to meet the customer's
stringent requirements of achieving Continuous Reliable Operation (CRO). Those building
blocks are: Error Prevention, Error Detection, Recovery, Problem Determination, Service
Structure, Change Management, and Measurement and Analysis.
The initial focus is on preventing failures from occurring in the first place. This is usually
accomplished by using “Hi-Rel” (highest reliability) components from our technology
suppliers, using screening, sorting, burn-in, run-in, and by taking advantage of technology
integration. For Licensed Internal Code (LIC) and hardware design, failures are eliminated
Number of z990 CPs
Base
Ratio
1 CP
z900-2C1
1.54 - 1.61
8 CPs
z900-2C8
1.52 - 1.56
16 CPs
z900-216
1.51 - 1.55
32 CPS
z900-216
2.46 - 2.98
301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332
Model B16
Model D32
Model C24
* S/W Model refers to number
of installed CPs. Reported by
STSI instruction. Model 300
does not have any CPs.
*
S/W
Model
Model A08