[ublas] timing of svd

From: Jack Nguyen (bluekite2000_at_[hidden])
Date: 2005-06-01 16:04:28

Why is duration here   
start=clock();
  for (int loop=0;loop<5;loop++)
        gesdd(A,S,U,V);
   finish=clock();
      duration=((double)(finish-start)/CLOCKS_PER_SEC)/5;

is significantly smaller than duration here
start=clock();
  for (int loop=0;loop<25;loop++)
        gesdd(A,S,U,V);
   finish=clock();
      duration=((double)(finish-start)/CLOCKS_PER_SEC)/25;

Also why does g++ -O3 doesnt speed up results at all??? Am I missing
something???