Initializing array made of 33554432 64-bit words (256.00 MiB).
Source pages allocated with transparent hugepages: 100.0% (65536 pages, 100.0% flagged)
Legend:
  BandW: Implied bandwidth (assuming 64-byte cache line) in MB/s
  % Eff: Effectiness of this lane count compared to the prior, as a % of ideal
  Speedup: Speedup factor for this many lanes versus one lane
Applying Sattolo's algorithm... chain total: 33554432
Time to sum up the array (linear scan) 0.023 s (x 8 = 0.181 s), bandwidth = 11319.4 MB/s 
Size: 33554432 (262144.00 KiB, 256.00 MiB)
---------------------------------------------------------------------
- # of lanes --- time (s) ---- BandW -- ns/hit -- % Eff -- Speedup --
---------------------------------------------------------------------
           1     3.355962        610     100.0       0%        1.0
           2     1.706550       1200      50.9      98%        2.0
           3     1.126794       1818      33.6     102%        3.0
           4     0.842254       2432      25.1     101%        4.0
           5     0.675952       3030      20.1      99%        5.0
           6     0.567640       3608      16.9      96%        5.9
           7     0.492100       4162      14.7      93%        6.8
           8     0.436062       4697      13.0      91%        7.7
           9     0.392760       5214      11.7      89%        8.5
          10     0.361735       5662      10.8      79%        9.3
          11     0.340245       6019      10.1      65%        9.9
          12     0.328044       6243       9.8      43%       10.2
          13     0.321959       6361       9.6      24%       10.4
          14     0.319588       6408       9.5      10%       10.5
          15     0.318986       6420       9.5       3%       10.5
          16     0.317439       6452       9.5       8%       10.6
          17     0.317806       6444       9.5      -2%       10.6
          18     0.317816       6444       9.5      -0%       10.6
          19     0.318095       6438       9.5      -2%       10.6
          20     0.318824       6424       9.5      -5%       10.5
          21     0.321546       6369       9.6     -18%       10.4
          22     0.322803       6344       9.6      -9%       10.4
          23     0.325242       6297       9.7     -17%       10.3
          24     0.322664       6347       9.6      19%       10.4
          25     0.325343       6295       9.7     -21%       10.3
          26     0.329830       6209       9.8     -36%       10.2
          27     0.333863       6134       9.9     -33%       10.1
          28     0.328187       6240       9.8      48%       10.2
          29     0.326749       6268       9.7      13%       10.3
          30     0.323578       6329       9.6      29%       10.4
          31     0.323648       6328       9.6      -1%       10.4
          32     0.324418       6313       9.7      -8%       10.3
          33     0.324123       6319       9.7       3%       10.4
          34     0.323251       6336       9.6       9%       10.4
          35     0.323844       6324       9.7      -6%       10.4
          36     0.324738       6307       9.7     -10%       10.3
          37     0.324587       6310       9.7       2%       10.3
          38     0.325455       6293       9.7     -10%       10.3
          39     0.325782       6286       9.7      -4%       10.3
          40     0.328242       6239       9.8     -30%       10.2
Maybe you have about 13 parallel paths? 
exit=0
