SPEC CPU2000: Read Me First
Last updated: 30-Oct-2001 jh
(To check for possible updates to this document, please see http://www.spec.org/cpu2000/docs/ )
|Suggested reading order|
|List of documents|
|SPEC CPU2000 Overview (What is it, and why does it exist?)|
|Q1. What is SPEC?|
|Q2. What is a benchmark?|
|Q3. Why use a benchmark?|
|Q4. What options are viable in this case?|
|Q5. What does SPEC CPU2000 measure?|
|Q6. Why use SPEC CPU2000?|
|Q7. What are the limitations of SPEC CPU2000?|
|Q8. What is included in the SPEC CPU2000 package?|
|Q9. What does the user of the SPEC CPU2000 suite have to provide?|
|Q10. What are the basic steps in running the benchmarks?|
|Q11. What source code is provided? What exactly makes up these suites?|
|Q12. Some of the benchmark names sound familiar; are these comparable to other programs?|
|Q13. What metrics can be measured?|
|Q14. What is the difference between a "base" metric and a "peak" metric?|
|Q15. What is the difference between a "rate" and a "speed" metric?|
|Q16. Which SPEC CPU2000 metric should be used to compare performance?|
|Q17. How do I contact SPEC for more information or for technical support?|
|Q18. Now that I've read this document, what should I do next?|
The SPEC CPU2000 documents are available in several locations:
|(Note: links to SPEC CPU2000 documents from this web page assume that you are reading the page in a directory that also contains the other documents. If by some chance you are reading this web page from a location where the links do not work, try accessing the referenced documents at one of the above locations.)|
If you are just getting started with SPEC CPU2000, here is a suggested reading order for the various documents supplied by SPEC:
|config.html||To run SPEC CPU2000, you need a config file. This document tells you how to write one.|
|errata.txt||Debugging and errata information.|
|example-advanced.cfg||A complex sample config file with commentary.|
|example-medium.cfg||A complete, but not very complex, sample config file with commentary.|
|example-simple.cfg||A simple configuration file with commentary. A first time user could take this as a template for a first run of SPEC CPU2000.|
|A new document, added for V1.1: how to use the SPEC-supplied tools for the shortest possible time, jump quickly into working with the source code, and run the benchmarks by hand.|
|install_guide_unix.html||How to install SPEC CPU2000 on UNIX systems. Includes an example installation and an example of running the first benchmark.|
|install_guide_nt.html||How to install SPEC CPU2000 on Windows/NT systems. Includes an example installation and an example of running the first benchmark.|
|legal.txt||Copyright notice and other legal information.|
|makevars.txt||Advanced users of the suite who want to understand exactly how the benchmarks are built can use this file to help decipher the process.|
|readme1st.html||The document you are reading now, contains a documentation overview and question and answers regarding the purpose and intent of SPEC CPU2000.|
|runrules.html||The SPEC CPU2000 Run and reporting rules. These must be followed for generating publicly disclosed results.|
|runspec.html||Information on the "runspec" command, which is the primary user interface for running SPEC CPU2000 benchmarks.|
|system_requirements.html||A list of the hardware and software needed in order to run the SPEC CPU2000 suite.|
|techsupport.txt||Information on SPEC technical support.|
|tools_build.txt||How to build (or re-build) the tools such as runspec|
|utility.html||How to use various utilities, such as specinvoke, specdiff, and specmake.|
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)
Only on the CD, you will find:
|original.src/README||Information about freely-available sources that have been incorporated in SPEC CPU2000|
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:
It is important to remember the contribution of the latter two components; performance is more than just the processor.
SPEC CPU2000 is made up of two subcomponents that focus on two different types of compute intensive performance:
Note that SPEC CPU2000 does not stress other computer components such as I/O (disk drives), networking, operating system or graphics. It might be possible to configure a system in such a way that one or more of these components impact the performance of CINT2000 and CFP2000, but that is not the intent of the suites.
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:
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:
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:
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
CFP2000 contains 14 applications (6 Fortran-77, 4 Fortran-90 and 4 C) that are used as benchmarks:
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
More detailed descriptions on the benchmarks (with reference to papers, web sites, etc.) can be found in the individual benchmark directories in the SPEC benchmark tree.
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):
CFP2000 (for floating point compute intensive performance comparisons:
The ratio for each of the benchmarks is calculated using a SPEC- determined reference time and the run time of the 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.
Note that the base metric rules are a subset of the peak metric rules. For example, a legal base metric is also legal under the peak rules but a legal peak metric is NOT legal under the base rules.
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.
For the rate metrics, multiple copies of the benchmarks are run simultaneously. Typically, the number of copies is the same as the number of CPUs on the machine, but this is not a requirement. For example, it would be perfectly acceptable to run 63 copies of the benchmarks on a 64-CPU machine (thereby leaving one CPU free to handle system overhead).
(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: email@example.com
CPU2000 Technical Support Questions can be sent to: firstname.lastname@example.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
and then you can install the suite, following the instructions in
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