Compute the CPU frequency by Java

By my previous article of "How to control the CPU occupation rate", someone came up with another idea - "How to get or compute the CPU frequency when I run the program in different PCs?"

That's really a challenge! But it's not a big problem by the same theory of CPU occupation control. We know now that CPU can run about 2 directives per tick, and the frequency is the count of ticks per second, and each for(i=0;i<n;i++) cycle contains about more than 5 ASM directives. By these estimated parameters, we will be able to compute the CPU frequency via a reverse computation engineering.

The source code is showed as below:

/* GetCPUFrequency.java
 *
 * TSUSOFT.NET, ALEXELA.CN
 * Copyright (C) 2007 by Alexandre Tsu
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
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 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
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 * Created on Aug 21, 2007, by Alexandre Tsu.
 *
 */

public class GetCPUFrequency
{
    public static void main(String[] args)
    {
        try
        {
            if(args.length != 2)
                printUsage();

            /* parameters estimation from input */
            float dpt = Float.parseFloat(args[0]);
            float dpc = Float.parseFloat(args[1]);

            System.out.print("Hit <Enter> to go on!");
            System.in.read();

            /* run cycles for Integer.MAX_VALUE times */
            long l1 = System.currentTimeMillis();
            for(int i=0; i<Integer.MAX_VALUE; i++);
            long l2 = System.currentTimeMillis();

            /* compute the cycles per second */
            long cps = Integer.MAX_VALUE / ( (l2 - l1) / 1000 );

            /* output the computation result */
            System.out.println("Directives per tick: " + dpt);
            System.out.println("Directives per cycle: " + dpc);
            System.out.println("Cycles per second: " + cps);
            System.out.println("CPU Frequency at: " + (cps * dpc / dpt));
        }
        catch(Throwable e)
        {
            printUsage();
        }
    }

    private static void printUsage()
    {
        System.out.println("Usage: java GetCPUFrequency dpt dpc");
        System.out.println("dpt: directives per tick");
        System.out.println("dpc: directives per cycle");
        System.exit(1);
    }
}

I tried running this program in different PCs (one with Windows and anther with Linux). I got a close result to my real CPU frequency. For my pratice, I estimated the two input parameters as 2 and 15. My actual CPU frequency is 1.40Ghz. One of run situation is as below:

D:\workspace\Test>java GetCPUFrequency 2 15
Hit <Enter> to go on!
Directives per tick: 2.0
Directives per cycle: 15.0
Cycles per second: 195225786
CPU Frequency at: 1.46419341E9