How fast is my desktop - 1.2GB/s

gistfile1.txt

/*
 * Note this just tests a single core:
 *
 * My work desktop: 1.2GB/s
 * My home desktop: 1.4GB/s
 * My raspberry pi: 200 MB/s
 */

#include <stdlib.h>
#include <stdio.h>
#include <sys/time.h>

double diff(struct timeval *after, struct timeval *before) {
    double result = 0;
    result += after->tv_sec - before->tv_sec;
    result += (after->tv_usec - after->tv_usec) / 1000000.0;
    return result;
}

int main(int argc, char **argv) {
    struct timeval before, after;
    int len1 = 1024 * 1024 * 100;
    int len2 = 100;
    int *buf = malloc(len1 * sizeof(int));
    int sum = 0;
    int i = 0;
    int j = 0;
    
    gettimeofday(&before, 0);
    for(j=0;j<len2;j++) {
      for(i=0;i<len1;++i) {
        sum += buf[i];
      }
    }
    gettimeofday(&after, 0);
    fprintf(stdout, "%lf MB/s\n", (len1 * len2 * sizeof(int)) / (1024.0 * 1024.0) / diff(&after, &before)); 
    return sum;
}

gcc -O -o test test.c