RS/6000 Introduction 11
SPEC95 introduces a new reference platform against which other systems
are measured, changing from the out-dated VAX 11/780 to a SPARCstation
10/40 with 64 MB memory but without Level 2 cache. This is more
representative of the types of systems being sold today, but it is also a
machine that will beat few, if any, of the machines being benchmarked.
The rules have also changed. Each benchmark must be run a minimum of
three times to get a valid result, with the median time for all runs being used
as the benchmark time.
The SPEC base metric (for example, SPECint_base95) are required for all
reported results and have set guidelines for compilation (for example, the
same four flags must be used in the same order for all benchmarks). The
non-base metrics (for example, SPECint95) are optional and have less
restrictive requirements (for example, different compiler options may be used
on each benchmark).
There are several different ways to measure computer performance. One way
is to measure how fast the computer completes a single task. This is a speed
measure. Another way is to measure how many tasks a computer can
accomplish in a certain amount of time. This is called a throughput, capacity,
or rate measure. The SPEC speed metrics (for example, SPECint95) are
used for comparing the ability of a computer to complete single tasks. The
SPEC rate metrics (for example, SPECint_rate95) measure the throughput or
rate of a machine carrying out a number of tasks.
The following SPEC and Linpack benchmarks reflect the performance of the
microprocessor, memory architecture, and compiler of the tested system.
SPECint95 SPEC component-level benchmark that measures
integer performance. Result is the geometric
mean of eight tests that comprise the CINT95
benchmark suite. All of these are written in C
language.
SPECint_base95 The result of the same tests in CINT95 with a
maximum of four compiler flags that must be used
in all eight tests.
SPECint_rate95 Geometric average of the eight SPEC rates from
the SPEC integer tests (CINT95).
SPECint_base_rate95 Geometric average of the eight SPEC rates from
the SPEC integer tests (CINT95) with the
restrictive compiler options.