Influence of frequency

Discussion in 'Embedded Systems and Microcontrollers' started by ga.eseco, Jul 28, 2009.

  1. ga.eseco

    Thread Starter New Member

    Jul 28, 2009

    I'm trying to understand how the frequency of a processor has an influence on how quickly a task will be completed.

    I've done some tests on a PXA270 for the company i'm working for and it appears that if I use a frequency, which is twice another, then the time required to complete a task is divided by two.

    I'm a little surprised with that result, it seems 'too simple', so I'm trying to figure out how I could explain it.

    For the test I just made the processor compelte a loop, also i'm not sure it's the best way to test the processor.

    Any idea on how I could explain this result, or maybe what kind of test I could run to go further.

    Last edited by a moderator: Jul 28, 2009
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    It is that simple.
  3. russ_hensel

    AAC Fanatic!

    Jan 11, 2009
    Unless you use delay routines or synchronize to outside events, I have a uc based clock that gives the right time despite which processor speed I pick ( time comes from the power line )
  4. mik3

    Senior Member

    Feb 4, 2008
    A processor simply transfers data between registers and does what it does. If you have a bucket and transfer water between two tanks, say one bucket every minute, what will happen if you transfer one bucket every half a minute?
    The tank will empty/fill twice as fast as before. It is the same idea except that a processor transfers data.
  5. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    It is that simple UNTIL you get to real-world interractions...

    If your program has to wait for anything external, whether it be a serial port, LCD or writing to flash memory, your actual gains will be rather less than the 'pure software' speed increase.
  6. atferrari

    AAC Fanatic!

    Jan 6, 2004
    What kind of post is that?

    A troll maybe?