-- Program 1
#include <stdio.h>

#define MAX_CNT 100

int main(int argc, char** argv)
{
    int i, j, k;
    int test_data[MAX_CNT][MAX_CNT][MAX_CNT];

    for(i = 0; i < MAX_CNT; i++)
    {
        for(j = 0; j < MAX_CNT; j++)
        {
            for(k = 0; k < MAX_CNT; k++)
            {
                test_data[i][j][k] = 100;
            }
        }
    }

    return 0;
}

Result
$ time ./main

real	0m0.008s
user	0m0.004s
sys	0m0.004s


-- Program 2
#include <stdio.h>

#define MAX_CNT 100


int main(int argc, char** argv)
{
    int i, j, k;
    int test_data[MAX_CNT][MAX_CNT][MAX_CNT];

    for(i = 0; i < MAX_CNT; i++)
    {
        for(j = 0; j < MAX_CNT; j++)
        {
            for(k = 0; k < MAX_CNT; k++)
            {
                test_data[k][j][i] = 100;
            }
        }
    }

    return 0;
}

$ time ./main

real	0m0.017s
user	0m0.013s
sys	0m0.004s