ChipKit Uno32 vs Arduino Uno - speed test

I wanted to make a speed comparison between Arduino Uno and ChipKit Uno 32.


Their price is similar 25 euros for Arduino Uno (from farnell) and 29 Euros for ChipKit Uno32.
However the hardware specs are much better for ChipKit (32 bit controller compared to only 16 bit for arduino. Also ChipKit has a higher frequency - 80 MHz compared to only 16 MHz). 


I have run a simple program which counts the number of prime numbers smaller than a limit.


You may find the test program at the end of this post. The same program was run on both platforms.

Results are as follows:

----------------------------------------------------------
prime numbers smaller than 10000


Arduino Uno:

• Duration: 2375 miliseconds
• Count primes: 1229

ChipKit Uno32:

• Duration: 98 miliseconds.
• Count primes: 1229

----------------------------------------------------------
prime numbers smaller than 20000


Arduino Uno:

• Duration: 5757 miliseconds.
• Count primes: 2262

ChipKit Uno32:

• Duration: 204 miliseconds.
• Count primes: 2262

----------------------------------------------------------
prime numbers smaller than 30000


Arduino Uno:

• Duration: 9737 miliseconds.
• Count primes: 3245

ChipKit Uno32:

• Duration: 323 miliseconds.
• Count primes: 3245

As you can see on the largest test, ChipKit is 30x faster than Arduino.

I could not test on significantly larger numbers because Arduino is only 16bits microcontroller (the largest number that can fit is 2^16).

The program is:

----------------------------------------------------------------------


bool isPrime(int p){


 if ( p == 2 ) return true;
 if ( p > 2 ){
   int m = sqrt(p);
  for(int i = 2; i <= m; ++i){
   if (p%i==0) return false;
  }
  return true;
 }
}


unsigned long time_start, time_stop, runtime;


void setup() {
 // initialize serial communications at 9600 bps:
 Serial.begin(9600);
}


int run_once = 0;


void loop(){
 if (!run_once){
   time_start = millis();


   int count_primes = 0;
   for(int i = 2; i <= 30000; ++i){
     if (isPrime(i))
       count_primes++;
   }


   time_stop = millis();
   runtime = time_stop - time_start;
   Serial.print("Duration: ");
   Serial.println(runtime);
   Serial.print("Count primes: ");
   Serial.println(count_primes );
   run_once = 1;
 }
}