118 lines
6.8 KiB
Markdown
118 lines
6.8 KiB
Markdown
% 
|
|
TimedExec – README
|
|
% by LoRd_MuldeR <<mulder2@gmx>> | <http://muldersoft.com/>
|
|
|
|
Introduction
|
|
============
|
|
|
|
**TimedExec** is a small utility for *benchmarking* command-line programs. It will *execute* the specified program with the specified command-line arguments and then *measure* the time that it takes for the execution to complete. In order to obtain *accurate* results, all measurements are implemented via *high-resolution* performance timers. And, since program execution times unavoidably are subject to certain variations (e.g. due to environmental noise), each test will be repeated *multiple* times. The number of metering passes can be configured as desired. Optionally, a number of "warm-up" passes can be performed *prior to* the first metering pass. The warm-up passes prevent caching effects from interfering with the execution times.
|
|
|
|
TimedExec will then compute the ***mean*** execution time as well as the ***median*** execution time of all metering passes. It will also record the *fastest* and *slowest* execution time that has been measured. Furthermore, TimedExec computes the *standard error* in order to determine ***confidence intervals*** from the benchmarking results^[[Konfidenzintervalle so einfach wie möglich erklärt](http://www.uni-siegen.de/phil/sozialwissenschaften/soziologie/mitarbeiter/ludwig-mayerhofer/statistik/statistik_downloads/konfidenzintervalle.pdf)]. These are the *ranges* which contain the program's “real” average execution time (expected value), *with very high probability*. All results will be saved to a log file.
|
|
|
|
|
|
Usage Instructions
|
|
==================
|
|
|
|
*TimedExec* uses a very simple command-line syntax. Just type **`TimedExec`**, followed by the program that you want to benchmark. Optionally, any number arguments can be appended; these parameters will be passed to the program.
|
|
|
|
***Note:*** Some options that influence the behavior of TimedExec can be controlled via environment variables.
|
|
|
|
```
|
|
===============================================================================
|
|
Timed Exec - Benchmarking Utility, Version 1.03
|
|
Copyright (c) 2018 LoRd_MuldeR <mulder2@gmx.de>. Some rights reserved.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License <http://www.gnu.org/>.
|
|
Note that this program is distributed with ABSOLUTELY NO WARRANTY.
|
|
===============================================================================
|
|
|
|
Usage:
|
|
TimedExec.exe <Program.exe> [Arguments]
|
|
|
|
Influential environment variables:
|
|
TIMED_EXEC_PASSES - Number of execution passes (default: 5)
|
|
TIMED_EXEC_WARMUP_PASSES - Number of warm-up passes (default: 1)
|
|
TIMED_EXEC_LOGFILE - Log-File Name (default: "TimedExec.log")
|
|
TIMED_EXEC_NO_CHECKS - Set this to *disable* exit code checks
|
|
```
|
|
|
|
Usage Example
|
|
-------------
|
|
|
|
In the following example we use *TimedExec* to benchmark the program **`ping.exe`** with the arguments **`-n 12 www.google.com`**. By default, the command will be executed *five* times, preceded by a single "warm-up" pass:
|
|
|
|
```
|
|
TimedExec.exe C:\Windows\System32\ping.exe -n 12 www.google.com
|
|
```
|
|
|
|
|
|
Results
|
|
=======
|
|
|
|
The resulting output, after all metering passes have been completed, looks like this:
|
|
```
|
|
===============================================================================
|
|
TEST COMPLETED SUCCESSFULLY AFTER 5 METERING PASSES
|
|
-------------------------------------------------------------------------------
|
|
Mean Execution Time : 11.257 seconds
|
|
Median Execution Time : 11.255 seconds
|
|
90% Confidence Interval : +/- 0.006 (0.053%) = [11.251, 11.263] seconds
|
|
95% Confidence Interval : +/- 0.007 (0.063%) = [11.250, 11.264] seconds
|
|
99% Confidence Interval : +/- 0.009 (0.083%) = [11.248, 11.266] seconds
|
|
Standard Deviation : 0.007 seconds
|
|
Standard Error : 0.004 seconds
|
|
Fastest / Slowest Pass : 11.253 / 11.270 seconds
|
|
===============================================================================
|
|
```
|
|
|
|
Interpretation
|
|
--------------
|
|
|
|
When comparing measurement results, the ***mean*** (average) execution time may seem like the most obvious choice. However, it has to be noted that the *mean* of a data sample is highly sensitive to “outliers” and therefore can be misleading! This is especially true, when there exists a lot of variation in the data sample. Consequently, comparing the ***median*** execution times usually is the preferable choice. That is because the *median* of a data sample is much more robust against outliers.
|
|
|
|
Furthermore, it is important to keep in mind that the *mean* (or *median*) execution time computed from a limited number of metering passes only yields an ***estimate*** of the program's “real” average execution time (expected value). The “real” value can only be determined accurately from an *infitinte* number of metering passes – which is **not** possible in practice. In this situation, we can have a look at the ***confidence intervals***. These intervals contain the “real” value, *with very high probability*. The most commonly used *confidence interval* is the “95%” one (higher confidence means broader interval, and vice versa).
|
|
|
|
Simply put, as long as the confidence intervals of program A and program B *overlap* (at least partially), we **must not** conclude that either of these programs runs faster (or slower) in the average case. ***No*** conclusion can be drawn in that case!
|
|
|
|
|
|
Sources
|
|
=======
|
|
|
|
The *TimedExec* source codes are managed by [**Git**](http://git-scm.com/doc) and are available from one of the official mirrors:
|
|
|
|
* <tt>https://github.com/lordmulder/TimedExec.git</tt> ([Browse](https://github.com/lordmulder/TimedExec))
|
|
* <tt>https://bitbucket.org/muldersoft/timedexec.git</tt> ([Browse](https://bitbucket.org/muldersoft/timedexec))
|
|
* <tt>https://gitlab.com/timedexec/timedexec.git</tt> ([Browse](https://gitlab.com/timedexec/timedexec))
|
|
|
|
|
|
License
|
|
=======
|
|
|
|
TimedExec is released under the terms of the [GNU General Public License](http://www.gnu.org/licenses/gpl-2.0.html), version 2.
|
|
|
|
```
|
|
Timed Exec - Command-Line Benchmarking Utility
|
|
Copyright (c) 2018 LoRd_MuldeR <mulder2@gmx.de>. Some rights reserved.
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License
|
|
as published by the Free Software Foundation; either version 2
|
|
of the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
http://www.gnu.org/licenses/gpl-2.0.txt
|
|
```
|
|
|
|
<br>
|
|
|
|
**e.o.f.**
|