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Subject: More Crafty SMP speedup numbers (BK test on opteron data)

Author: Robert Hyatt

Date: 22:02:03 05/07/04


I finally located the BK test runs that I had cleverly tucked away in a
directory "out of the way" so they wouldn't get removed by accident.  Here is
the summary.  The raw logs are again at ftp.cis.uab.edu/pub/hyatt/smpdata and
the filenames start with "kp" rather than the CB positions I put there for
Martin.

Here is the 2cpu summary:

pos 1cpu      2cpua     2cpub     2cpuc     2cpud
  2   34     51/0.67   25/1.36   28/1.21   35/0.97
  3  139     51/2.73   45/3.09   58/2.40   74/1.88
  4  154    106/1.45   84/1.83   83/1.86   84/1.83
  5  175    112/1.56  105/1.67  114/1.54  109/1.61
  6  145     69/2.10   70/2.07   74/1.96   70/2.07
  7  110     65/1.69   71/1.55  112/0.98  111/0.99
  8  115     60/1.92   66/1.74   58/1.98   60/1.92
  9  171    101/1.69  104/1.64  101/1.69   94/1.82
 10   95     45/2.11   43/2.21   38/2.50   41/2.32
 11   97     35/2.77   55/1.76   52/1.87   56/1.73
 12  147    100/1.47  113/1.30  107/1.37  114/1.29
 13  153    108/1.42   98/1.56   79/1.94   83/1.84
 14  137     75/1.83   88/1.56   81/1.69   87/1.57
 15   86     42/2.05   42/2.05   41/2.10   42/2.05
 16  141     78/1.81   78/1.81   78/1.81   77/1.83
 17   38     25/1.52   21/1.81   23/1.65   21/1.81
 18  154     95/1.62   60/2.57   91/1.69   72/2.14
 19  128     67/1.91   57/2.25   65/1.97   58/2.21
 20   96     66/1.45   63/1.52   66/1.45   66/1.45
 21  123     70/1.76   70/1.76   67/1.84   74/1.66
 22   98     46/2.13   48/2.04   45/2.18   45/2.18
 23  137     62/2.21   61/2.25  106/1.29  106/1.29
 24   87     45/1.93   43/2.02   39/2.23   44/1.98
average SU      1.82      1.89      1.79      1.76


The first col is the BK position number (1 is omitted as it is not a useful
position for smp testing, it is solved too quickly to measure anything).  second
col is the raw 1cpu time for the last iteration completed in common with all the
SMP test runs.  The next 4 columns are pairs of numbers.  First number is
integer time in seconds for that position, second is floating point speedup to 2
decimel places.  Repeated four times for four different runs.  Bottom of each
column is the speedup for that column summed and divided by 23...

Here is the same data for the 4 cpu runs:

pos 1cpu      4cpua     4cpub     4cpuc     4cpud
  2   34     26/1.31   27/1.26   18/1.89   18/1.89
  3  139     54/2.57   29/4.79   75/1.85   75/1.85
  4  154     49/3.14   46/3.35   52/2.96   52/2.96
  5  175     71/2.46   53/3.30   58/3.02   58/3.02
  6  145     34/4.26   33/4.39   51/2.84   51/2.84
  7  110     61/1.80   73/1.51   43/2.56   43/2.56
  8  115     37/3.11   39/2.95   35/3.29   35/3.29
  9  171     67/2.55   37/4.62   41/4.17   41/4.17
 10   95     42/2.26   28/3.39   40/2.38   40/2.38
 11   97     30/3.23   27/3.59   32/3.03   32/3.03
 12  147     77/1.91   55/2.67   63/2.33   63/2.33
 13  153     55/2.78   56/2.73   40/3.83   40/3.83
 14  137     47/2.91   42/3.26   39/3.51   39/3.51
 15   86     26/3.31   26/3.31   25/3.44   25/3.44
 16  141     51/2.76   50/2.82   47/3.00   47/3.00
 17   38     12/3.17   13/2.92   13/2.92   13/2.92
 18  154     50/3.08   50/3.08   79/1.95   79/1.95
 19  128     38/3.37   38/3.37   30/4.27   30/4.27
 20   96     30/3.20   36/2.67   25/3.84   25/3.84
 21  123     42/2.93   44/2.80   43/2.86   43/2.86
 22   98     24/4.08   24/4.08   25/3.92   25/3.92
 23  137     76/1.80   61/2.25   46/2.98   46/2.98
 24   87     31/2.81   32/2.72   33/2.64   33/2.64
average SU      2.82      3.12      3.02      3.02


A couple of notes.  GCP and Vincent claimed these would be "better" for SMP
results.  I said no.  Data says no.  The answer is "no".  At least in the case
of Crafty.  I won't speak for other programs.

Speedups were close to the DTS position tests posted yesterday, although the 4
processor tests are not quite as good.

Now I guess perhaps with 18 log files, two different test sets, it is reasonable
to conclude that my formula is pretty close.  It will never be "perfect" as it
has no randomness built in, while the actual data always varies from run to run.

Arguing about "3.1 is wrong" is stupid.  Because that argument can be made for
_any single speedup number_ as I have said many times.  Speedup numbers are
relative to the test position set, the program, and even a bit of
luck/randomness tossed in.

Perhaps much urban legend can be tossed out the door now and real factual
numbers can be referenced..

Of course now Vincent is off on a new tangent explaining why my speedup numbers
are not fair.  Because I might be able to make the program as much as 2% faster,
and probably less on the Opteron, if I removed the TREE pointer required for the
SMP search.  To that I simply say "bullshit".  :)

Note:

In the above data, I will give the same disclaimer as Martin.  I copied the
numbers and converted in my head.  There _could_ be errors although I don't
believe there are.  Someone could check if they really care.  I'm tired enough
to say "I don't right now."  :)





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