title: for loops on openmp
body: <p>The following code is running faster when I dont use openMP. Why is it so?
  I am running it on a dual core machine.
  The time taken to run using open mp is about 0.05 sec while it takes only 0.03 sec when I run it without openMP.</p>
  
  <pre><code>#include&lt;omp.h&gt;
  #include&lt;iostream&gt;
  #include&lt;time.h&gt;
  using namespace std;
  
  int main()
  {
  clock_t start=clock();
  int i,j,t1,t2, n=1;
  float a[1000][1000];
  float b[1000][1000];
  
  
  
  #pragma omp parallel 
  {
  #pragma omp for private(i)
  for(j=0; j&lt;1000; j++)
  {
      for(i=0; i&lt;1000; i++)
  
  
      {
              a[i][j]=(i*j*i*j)/(i+j+1)/(i*j*i+8*i+1);
              b[i][j]=(i*j*i*j)/(i+j+1)/(i*j*i+8*i+1);
  
      }
  }
  }
  clock_t end=clock();
  cout&lt;&lt;"Time to run is "&lt;&lt;(double)(end - start)/CLOCKS_PER_SEC&lt;&lt;endl;
  }
  </code></pre>