Order 7 Bent Diagonal Notes

Programs

The computation was divided into 22 programs - each specifying a number 1 .. 22 for the upper left corner a1 value. These programs were run 4 at a time - 3 on a HP Z800 workstation and 1 on a HP a6220n desktop.

Results

       a1           squares        backtracks       run time    computer
     -----          -------      --------------    ----------   --------

     > 22                0                    3      00:00:00    HP Z800
       22              141        1,592,435,141      26:22:53    HP Z800
       21               36        2,399,660,087      26:37:16    HP Z800

       20              230        6,520,340,357     123:04:31    HP Z800
       19              306        9,760,020,944     192:22:52    HP Z800
       18              378       14,515,716,558     293:17:49    HP Z800
       17              267       16,906,545,579     357:10:42    HP Z800
       16              582       23,900,516,586     511:01:16    HP Z800

       15              645       24,751,453,007     540:58:52    HP Z800
       14              992       32,264,761,859     711:45:08    HP Z800
       13              989       33,150,614,988     717:45:05    HP Z800
       12             1839       43,448,474,988     927:59:34    HP Z800
       11             1305       37,462,578,764     799:41:13    HP Z800

       10             1795       43,045,203,035     912:48:41    HP Z800
        9             1343       36,446,566,365     768:04:17    HP Z800
        8             1818       40,663,529,382     852:57:28    HP Z800
        7             1093       35,349,754,281     722:48:36    HP Z800
        6             1316       39,080,645,731     809:31:51    HP Z800

        5             1075       28,177,354,685     491:29:08    HP Z800
                                                                  & a6220n
        4             1347       38,167,800,595     931:05:05    HP a6220n
        3             1165       31,486,308,056     753:43:25    HP a6220n
        2             1562       35,829,290,584     855:37:00    HP a6220n
        1             1222       25,347,152,583     415:37:25    HP a6220n
     -----          -------     ---------------   -----------
      all           21,446      600,269,724,155   12741:51:35

Distribution

Time Stats

The biggest number of squares made in 1 second was 32, numbers 242 to 273, of the a1 = 1 squares.
The longest time interval between squares was 41:55:35 between numbers 994 and 995 of the a1 = 3 squares.
The average of the time intervals, (before the first square, between squares, and after the last square in each run), was 00:35:36.

The squares here are in the order produced with the same aspect.

Equipment

Computers

  Model:              HP Z800
  Processor:          Intel® Xeon® CPU E5620 @ 2.40GHz 2.40GHz
  Operating System:   Windows 7 Professional 64-bit

  Model:              HP a6220n
  Processor:          Intel® Core™2 Duo CPU E4500 @ 2.20GHz 2.20GHz
  Operating System:   Windows Vista® Home Premium 32-bit

Uninteruptible Power Supply

  Model:              APC Back-UPS® Pro 1000

Backup Power

  Model:              YAMAHA EF2000iS Inverter