IBM Power System POWER7 Series, Optimization And Tuning Manual

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POWER7 and Optimization and Tuning Guide
These performance tools are most often used as part of the advanced investigative
techniques that are described in 1.5, “Optimizing performance on POWER7” on page 5,
except for the new performance advisors, which are intended as investigative tools,
appropriate for a broader audience of users.
򐂰 Appendix C, “POWER7 optimization and tuning with third-party applications” on page 185
describes preferred practices for migrating third-party products (Oracle, Sybase ASE and
Sybase IQ, SAS, and SAP) to Power Systems. We describe implementation tasks and
how to meet environment requirements. Links to comprehensive documentation about
current migrations are included.
After you review the advice in this guide, and if you would like more information, begin by
visiting the IBM Power Systems website at:
http://www.ibm.com/systems/power/index.html
1.3 Conventions that are used in this guide
In this guide, our convention for indicating sections of code or command examples is shown in
Table 1-1.
Table 1-1 Conventions that are used in this guide
1.4 Background
Some trends in processor design are making it more important than ever to consider
analyzing and working to improve application performance. In the past, two of the ways in
which newer processor chips delivered higher performance were by:
򐂰
Increasing the clock rate
򐂰
Making microarchitectural improvements that increase the performance of a single thread
Often, upgrading to a new processor chip gave existing applications a 50% or possibly 100%
performance improvement, leaving little incentive to spend much effort to get an uncertain
amount of additional performance. However, the approach in the industry has shifted, so that
the newer processor chips do not substantially increased clock rates, as compared to the
previous generation. In some cases, clock rates declined in newer designs. Recent designs
also generally offer more modest improvements in the performance of a single execution
thread.
Type of example Format that is
used in this
guide Example of our convention
Commands and command
options within text Monofont,
bolded ldedit
Command lines or code
examples outside of text Monofont ldedit -btextpsize=64k -bdatapsize=64k
-bstackpsize=64k
Variables in command lines Monofont,
italicized ldedit -btextpsize=64k -bdatapsize=64k
-bstackpsize=64k <
executable >
Variables that are limited to
specific choices Monofont,
italicized -mcmodel={
medium
|
large
}