[pserwylo]

You should check out a tool I heard about recently called "ministat". An example of how to use it to benchmark multiple runs, and then compute the statistics from each run are available here:

http://anholt.net/compare-perf/

Example output:

  +------------------------------------------------------------------------------+
  |                   +                            x                             |
  |                   +                            x                             |
  |           +       +                            x x            x              |
  | +    ++   +++     +                            x xxx xx       x              |
  |++ ++++++++++++++++++                   x  x    x xxx xxx  xxxxx              |
  |++ ++++++++++++++++++ +++ +       ++   xxxxxxxxxx xxxxxxxxxxxxxxxx  xx x    xx|
  |     |______MA______|                        |________A________|              |
  +------------------------------------------------------------------------------+
      N           Min           Max        Median           Avg        Stddev
  x  57      45.62364     46.437353      45.93506     45.951554    0.19060973
  +  57     44.785579     45.534727     45.042576     45.056702    0.16634531
  Difference at 95.0% confidence
    -0.894852 +/- 0.0656777
    -1.94738% +/- 0.142928%
    (Student's t, pooled s = 0.178889)