SPEC CPU2000: Read Me First

• www.spec.org/cpu2000/docs/
• The $SPEC/docs/ directory on a Unix system where SPEC CPU2000 has been installed.
• The %spec%\docs.nt\ directory on a Windows/NT system where SPEC CPU2000 has been installed.
• The docs/ or docs.nt\ directory on your SPEC CPU2000 distribution cdrom.

1. readme1st.html (the document you are reading now)
2. system_requirements.html
3. install_guide_unix.html or install_guide_nt.html
4. runspec.html
5. other documents as needed

In addition, each individual benchmark in the suite has its own documents, found in the benchmark "docs" subdirectory. For example, the description of the benchmark 164.gzip may be found in:

     $SPEC/benchspec/CINT2000/164.gzip/docs/164.gzip.txt (Unix) or
    %SPEC%\benchspec\CINT2000\164.gzip\docs\164.gzip.txt (NT)
  

SPEC CPU2000 Overview (What is it, and why does it exist?)

Background

By providing this background, SPEC hopes to help users set their expectations and usage appropriately to get the most efficient and beneficial use out of this benchmark product.

Overall, SPEC designed SPEC CPU2000 to provide a comparative measure of compute intensive performance across the widest practical range of hardware. This resulted in source code benchmarks developed from real user applications. These benchmarks are dependent on the processor, memory and compiler on the tested system.

Q1. What is SPEC?

SPEC is an acronym for the Standard Performance Evaluation Corporation. SPEC is a non-profit organization composed of computer vendors, systems integrators, universities, research organizations, publishers and consultants whose goal is to establish, maintain and endorse a standardized set of relevant benchmarks for computer systems. Although no one set of tests can fully characterize overall system performance, SPEC believes that the user community will benefit from an objective series of tests which can serve as a common reference point.

Q2. What is a benchmark?

The definition from Webster's II Dictionary states that a benchmark is "A standard of measurement or evaluation." A computer benchmark is typically a computer program that performs a strictly defined set of operations (a workload) and returns some form of result (a metric) describing how the tested computer performed. Computer benchmark metrics usually measure speed (how fast was the workload completed) or throughput (how many workloads per unit time were measured). Running the same computer benchmark on multiple computers allows a comparison to be made.

Q3. Why use a benchmark?

Ideally, the best comparison test for systems would be your own application with your own workload. Unfortunately, it is often very difficult to get a wide base of reliable, repeatable and comparable measurements for comparisons of different systems on your own application with your own workload. This might be due to time, money, confidentiality, or other constraints.

Q4. What options are viable in this case?

At this point, you can consider using standardized benchmarks as a reference point. Ideally, a standardized benchmark will be portable and maybe already run on the platforms that you are interested in. However, before you consider the results you need to be sure that you understand the correlation between your application/computing needs and what the benchmark is measuring. Are the workloads similar and do they have the same characteristics? Based on your answers to these questions, you can begin to see how the benchmark may approximate your reality.

Note: It is not intended that the SPEC benchmark suites be used as a replacement for the benchmarking of actual customer applications to determine vendor or product selection.

Q5. What does SPEC CPU2000 measure?

SPEC CPU2000 focuses on compute intensive performance, which means these benchmarks emphasize the performance of:

• the computer's processor (CPU),
• the memory architecture, and
• the compilers.

SPEC CPU2000 is made up of two subcomponents that focus on two different types of compute intensive performance:

• CINT2000 for measuring and comparing compute-intensive integer performance, and
• CFP2000 for measuring and comparing compute-intensive floating point performance.

Q6. Why use SPEC CPU2000?

As mentioned above, SPEC CPU2000 provides a comparative measure of integer and/or floating point compute intensive performance. If this matches with the type of workloads you are interested in, SPEC CPU2000 provides a good reference point.

Other advantages to using SPEC CPU2000:

• Benchmark programs are developed from actual end-user applications as opposed to being synthetic benchmarks.
• Multiple vendors use the suite and support it.
• SPEC CPU2000 is highly portable.
• A wide range of results are available at http://www.spec.org
• The benchmarks are required to be run and reported according to a set of rules to ensure comparability and repeatability.

Q7. What are the limitations of SPEC CPU2000?

As described above under "Why use a benchmark?", the ideal benchmark for vendor or product selection would be your own workload on your own application. Please bear in mind that no standardized benchmark can provide a perfect model of the realities of your particular system and user community.

Q8. What is included in the SPEC CPU2000 package?

SPEC provides the following on the SPEC CPU2000 Media:

• Source code for the CINT2000 benchmarks
• Source code for the CFP2000 benchmarks
• A tool set for compiling, running, validating and reporting on the benchmarks
• Pre-compiled tools for a variety of operating systems.
• Source code for the SPEC CPU2000 tools, for systems not covered by the pre-compiled tools
• Run and reporting rules defining how the benchmarks should be used to produce SPEC CPU2000 results.
• Documentation

Q9. What does the user of the SPEC CPU2000 suite have to provide?

Briefly, you need a Unix or NT system with 256MB of memory, 1GB of disk, and a set of compilers. Please see the details in the file system_requirements.html

Q10. What are the basic steps in running the benchmarks?

Installation and use are covered in detail in the SPEC CPU2000 User Documentation. The basic steps are as follows:

• Install SPEC CPU2000 from media.
• Run the installation scripts to set up the appropriate directory structure and install (and build, if necessary) the SPEC CPU2000 tools.
• Determine which metric you wish to run.
• Read the Run and Reporting Rules to ensure that you understand the rules for generating that metric.
• Create a configuration file according to the rules for that metric. In this file, you specify compiler flags and other system-dependent information. The example-simple.cfg file contains a template for creating an initial config file. After you become comfortable with this, you can read other documentation to see how you can use the more complex features of the SPEC CPU2000 tools.
• Run the SPEC tools to build (compile), run and validate the benchmarks.
• If the above steps are successful, generate a report based on the run times and metric equations.

Q11. What source code is provided? What exactly makes up these suites?

CINT2000 and CFP2000 are based on compute-intensive applications provided as source code. CINT2000 contains eleven applications written in C and 1 in C++ (252.eon) that are used as benchmarks:

      Name        Ref Time Remarks
      164.gzip      1400   Data compression utility
      175.vpr       1400   FPGA circuit placement and routing
      176.gcc       1100   C compiler
      181.mcf       1800   Minimum cost network flow solver
      186.crafty    1000   Chess program
      197.parser    1800   Natural language processing
      252.eon       1300   Ray tracing
      253.perlbmk   1800   Perl
      254.gap       1100   Computational group theory
      255.vortex    1900   Object Oriented Database
      256.bzip2     1500   Data compression utility
      300.twolf     3000   Place and route simulator

      Name        Ref Time Remarks
      168.wupwise   1600   Quantum chromodynamics
      171.swim      3100   Shallow water modeling
      172.mgrid     1800   Multi-grid solver in 3D potential field
      173.applu     2100   Parabolic/elliptic partial differential
                           equations
      177.mesa      1400   3D Graphics library
      178.galgel    2900   Fluid dynamics: analysis of oscillatory instability
      179.art       2600   Neural network simulation; adaptive resonance theory
      183.equake    1300   Finite element simulation; earthquake modeling
      187.facerec   1900   Computer vision: recognizes faces
      188.ammp      2200   Computational chemistry 
      189.lucas     2000   Number theory: primality testing
      191.fma3d     2100   Finite element crash simulation
      200.sixtrack  1100   Particle accelerator model
      301.apsi      2600   Solves problems regarding temperature, wind,
                           velocity and distribution of pollutants

The numbers used as part of the benchmarks names provide an identifier to help distinguish programs from one another. For example, some programs were updated from SPEC CPU95 and need to be distinguished from their previous version.

Q12. Some of the benchmark names sound familiar; are these comparable to other programs?

Many of the SPEC benchmarks have been derived from publicly available application programs and all have been developed to be portable to as many current and future hardware platforms as practical. Hardware dependencies have been minimized to avoid unfairly favoring one hardware platform over another. For this reason, the application programs in this distribution should not be used to assess the probable performance of commercially available, tuned versions of the same application. The individual benchmarks in this suite may be similar, but NOT identical to benchmarks or programs with the same name which are available from sources other than SPEC; therefore, it is not valid to compare SPEC CPU2000 benchmark results with anything other than other SPEC CPU2000 benchmark results. (Note: This also means that it is not valid to compare SPEC CPU2000 results to older SPEC CPU benchmarks; these benchmarks have been changed and should be considered different and not comparable.)

Q13. What metrics can be measured?

The CINT2000 and CFP2000 suites can be used to measure and calculate the following metrics:

CINT2000 (for integer compute intensive performance comparisons):

• SPECint2000: The geometric mean of twelve normalized ratios (one for each integer benchmark) when compiled with aggressive optimization for each benchmark.
• SPECint_base2000: The geometric mean of twelve normalized ratios when compiled with conservative optimization for each benchmark.
• SPECint_rate2000: The geometric mean of twelve normalized throughput ratios when compiled with aggressive optimization for each benchmark.
• SPECint_rate_base2000: The geometric mean of twelve normalized throughput ratios when compiled with conservative optimization for each benchmark.

• SPECfp2000: The geometric mean of fourteen normalized ratios (one for each floating point benchmark) when compiled with aggressive optimization for each benchmark.
• SPECfp_base2000: The geometric mean of fourteen normalized ratios when compiled with conservative optimization for each benchmark.
• SPECfp_rate2000: The geometric mean of fourteen normalized throughput ratios when compiled with aggressive optimization for each benchmark.
• SPECfp_rate_base2000: The geometric mean of fourteen normalized throughput ratios when compiled with conservative optimization for each benchmark.

A higher score means "better performance" on the given workload.

Q14. What is the difference between a "base" metric and a "peak" metric?

In order to provide comparisons across different computer hardware, SPEC provides the benchmarks as source code. Thus, in order to run the benchmarks, they must be compiled. There is agreement that the benchmarks should be compiled the way users compile programs. But how do users compile programs?

Some people might experiment with many different compilers and compiler flags to achieve the best performance. Other people might just compile with the basic options suggested by the compiler vendor. SPEC recognizes that it cannot exactly match how everyone uses compilers, but two reference points are possible:

• The base metrics (e.g. SPECint_base2000) are required for all reported results and have set guidelines for compilation. For example, the same flags must be used in the same order for all benchmarks, and only a limited number of flags are allowed. This is the point closest to those who simply use the recommended compiler flags for compilation.

• The peak metrics (e.g. SPECint2000) are optional and have less strict requirements. For example, different compiler options may be used on each benchmark. This is the point closest to those who may experiment with different compiler options to get the best possible performance possible.

A full description of the distinctions and required guidelines can be found in the SPEC CPU2000 Run and Reporting Rules available with SPEC CPU2000.

Q15. What is the difference between a "rate" and a "speed" metric?

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 (e.g., SPECint2000) are used for comparing the ability of a computer to complete single tasks.
• The SPEC rate metrics (e.g., SPECint_rate2000) measure the throughput or rate of a machine carrying out a number of tasks.

(Note: a speed run which uses a parallelizing compiler to distribute one copy of a benchmark over multiple CPUs is still a speed run, and uses the speed metrics. You can identify such runs by the field "parallel", newly introduced with CPU2000.)

Q16. Which SPEC CPU2000 metric should be used to compare performance?

It depends on your needs. SPEC provides the benchmarks and results as tools for you to use. You need to determine how you use a computer or what your performance requirements are and then choose the appropriate SPEC benchmark or metrics.

A single user running a compute-intensive integer program, for example, might only be interested in SPECint2000 or SPECint_base2000. On the other hand, a person who maintains a machine used by multiple scientists running floating point simulations might be more concerned with SPECfp_rate2000 or SPECfp_rate_base2000.

Q17. How do I contact SPEC for more information or for technical support?

SPEC can be contacted in several ways. For general information, including other means of contacting SPEC, please see SPEC's World Wide Web Site at:

General questions can be emailed to: info@spec.org
CPU2000 Technical Support Questions can be sent to: cpu2000support@spec.org

Q18. Now that I've read this document, what should I do next?

You should verify that your system meets the requirements as described in