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) 0.007 s (x 8 = 0.053 s), bandwidth = 38711.6 MB/s 
Size: 33554432 (262144.00 KiB, 256.00 MiB)
---------------------------------------------------------------------
- # of lanes --- time (s) ---- BandW -- ns/hit -- % Eff -- Speedup --
---------------------------------------------------------------------
           1     2.759739        742      82.2       0%        1.0
           2     1.374553       1490      41.0     100%        2.0
           3     0.908561       2254      27.1     102%        3.0
           4     0.687434       2979      20.5      97%        4.0
           5     0.549941       3724      16.4     100%        5.0
           6     0.456720       4484      13.6     102%        6.0
           7     0.395688       5176      11.8      94%        7.0
           8     0.351186       5832      10.5      90%        7.9
           9     0.310011       6606       9.2     106%        8.9
          10     0.278272       7360       8.3     102%        9.9
          11     0.253199       8088       7.5      99%       10.9
          12     0.234384       8738       7.0      89%       11.8
          13     0.219185       9344       6.5      84%       12.6
          14     0.199710      10255       6.0     124%       13.8
          15     0.190153      10770       5.7      72%       14.5
          16     0.179139      11432       5.3      93%       15.4
          17     0.168062      12186       5.0     105%       16.4
          18     0.162440      12608       4.8      60%       17.0
          19     0.159071      12875       4.7      39%       17.3
          20     0.158153      12949       4.7      12%       17.4
          21     0.159279      12858       4.7     -15%       17.3
          22     0.157699      12987       4.7      22%       17.5
          23     0.157971      12964       4.7      -4%       17.5
          24     0.161237      12702       4.8     -50%       17.1
          25     0.157252      13024       4.7      62%       17.5
          26     0.155750      13149       4.6      25%       17.7
          27     0.157672      12989       4.7     -33%       17.5
          28     0.156587      13079       4.7      19%       17.6
          29     0.156443      13091       4.7       3%       17.6
          30     0.156865      13056       4.7      -8%       17.6
          31     0.160267      12779       4.8     -67%       17.2
          32     0.165385      12383       4.9    -102%       16.7
          33     0.164586      12443       4.9      16%       16.8
          34     0.162861      12575       4.9      36%       16.9
          35     0.163023      12563       4.9      -3%       16.9
          36     0.180473      11348       5.4    -385%       15.3
          37     0.183582      11156       5.5     -64%       15.0
          38     0.171779      11922       5.1     244%       16.1
          39     0.172393      11880       5.1     -14%       16.0
          40     0.172258      11889       5.1       3%       16.0
Maybe you have about 19 parallel paths? 
exit=0
