0:  real 23.99 user 0.05 sys 19.27
1:  real 24.67 user 0.05 sys 19.65
2:  real 24.45 user 0.04 sys 19.46
3:  real 23.95 user 0.05 sys 19.05
0:  262144+0 records in 262144+0 records out real 5.97 user 0.08 sys 5.89
1:  262144+0 records in 262144+0 records out real 5.66 user 0.08 sys 5.58
2:  262144+0 records in 262144+0 records out real 5.73 user 0.08 sys 5.64
3:  262144+0 records in 262144+0 records out real 5.76 user 0.08 sys 5.67