Speed trials list

TimC

HI All,
In the April Issue of Nuts and Volts there was an article by Chuck Hellebuyck about running a simple test to see how processors compared in speed. Since I have a bunch of chips myself I thought it would be fun to compare more. I ran all the chips at the top speed so in the case of the PIC's and AVR chips they are all running at 20Mhz. I agree with everything he printed in Nuts and volts so I combined it all:

PICAXE 28x @4mhz 368msec from N&V BasicStamp2 278msec Basic Atom 68msec from N&V BS2px24 60msec Javelin 22msec PICBasic PRO PIC16F877 0.350msec CCS 'C' PIC16FF877 0.350msec GCC 'C' Mega32 0.192msec ARM LPC2148 0.065msec

The task is how fast can the processor increment a variable 255 times
For the basic stamp here is the code:

'{$STAMP BS2px}
'{$PBASIC 2.5}

' connections
LED    PIN 0
' variables
x      var byte
y      var byte

Main:
'this program will loop forever

   high LED
   for x=1 to 255
      y=y+1
   next
   low LED
   pause 10

   goto Main

end

In the 'C' world the code is like this (the delay is shorter so I can measure the ON period better)

do {
        output_high(TEST_PIN);    // turn on voltage
        z=254;
        for(; z; --z)
            y++;
        output_low(TEST_PIN);     // turn off
        delay_ms(1);           // lets delay.
   
   } while (1);

If anyone has anything they want to try please add it.
Regards
Tim

Paul Baker

I calculate the propeller·would take ·25.5 uS for the incrementing loop, plus whatever setup is required, oh yeah and it will do it eightfold simulatenously [noparse]:)[/noparse].

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.