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) 0.013 s (x 8 = 0.104 s), bandwidth = 19692.3 MB/s 
Size: 33554432 (262144.00 KiB, 256.00 MiB)
---------------------------------------------------------------------
- # of lanes --- time (s) ---- BandW -- ns/hit -- % Eff -- Speedup --
---------------------------------------------------------------------
           1     3.269646        626      97.4       0%        1.0
           2     1.640191       1249      48.9     100%        2.0
           3     1.091195       1877      32.5     100%        3.0
           4     0.824812       2483      24.6      98%        4.0
           5     0.660806       3099      19.7      99%        4.9
           6     0.550554       3720      16.4     100%        5.9
           7     0.475823       4304      14.2      95%        6.9
           8     0.414177       4945      12.3     104%        7.9
           9     0.367409       5574      10.9     102%        8.9
          10     0.334045       6131      10.0      91%        9.8
          11     0.304872       6718       9.1      96%       10.7
          12     0.288813       7091       8.6      63%       11.3
          13     0.283847       7215       8.5      22%       11.5
          14     0.282917       7239       8.4       5%       11.6
          15     0.283224       7231       8.4      -2%       11.5
          16     0.283838       7215       8.5      -3%       11.5
          17     0.280945       7290       8.4      17%       11.6
          18     0.283174       7232       8.4     -14%       11.5
          19     0.280345       7305       8.4      19%       11.7
          20     0.280659       7297       8.4      -2%       11.6
          21     0.281066       7287       8.4      -3%       11.6
          22     0.280426       7303       8.4       5%       11.7
          23     0.281790       7268       8.4     -11%       11.6
          24     0.282138       7259       8.4      -3%       11.6
          25     0.279206       7335       8.3      26%       11.7
          26     0.280512       7301       8.4     -12%       11.7
          27     0.281255       7282       8.4      -7%       11.6
          28     0.281430       7277       8.4      -2%       11.6
          29     0.281554       7274       8.4      -1%       11.6
          30     0.279046       7339       8.3      27%       11.7
          31     0.279220       7335       8.3      -2%       11.7
          32     0.278921       7343       8.3       3%       11.7
          33     0.279462       7328       8.3      -6%       11.7
          34     0.277931       7369       8.3      19%       11.8
          35     0.279020       7340       8.3     -14%       11.7
          36     0.279247       7334       8.3      -3%       11.7
          37     0.279837       7319       8.3      -8%       11.7
          38     0.279686       7322       8.3       2%       11.7
          39     0.280373       7305       8.4     -10%       11.7
          40     0.280118       7311       8.3       4%       11.7
Maybe you have about 13 parallel paths? 
exit=0
