Subject: Stabilizing time measurements
        Date: Thu, 08 Mar 2001 18:23:40 -0500
        From: Igor Markov <imarkov@umich.edu>
Organization: U. of Michigan, EECS
  Newsgroups: umich.eecs.class.380

   In addition to previously posted pieces of advice
   (increase the array size, average over many experiments),
   here's something may be helpful.
 
   Use the  top   command to see if anyone is running programs
   on your machine. Also use finger to see who is logged in.
   Some of the engine machines may run simulations launched
   by 2-3 students, mailers, newsreaders, etc. While user time
   gives the time spent by your program only (versus the astronomic time),
   this very time may considerably vary depending on what other programs do
   (since all programs share the same processor cache and memory bus).

   Therefore you may want to find a machine not used by anyone else
   (e.g., at night or in the morning) and launch your experiments on it.
   
   See which Sun workstations are not used:
      http://www.engin.umich.edu/htbin/hostinfo
   login remotely, check that the load is low and run your time tests.

                                                        Igor
-- 
   Igor Markov         (734) 936-7829       EECS 2211
   http://www.eecs.umich.edu/~imarkov