MathGroup Archive 1997

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Mathematica 3.01 is slower than Mathematica 3.0 on PowerMacs!

  • To: mathgroup at smc.vnet.net
  • Subject: [mg9775] Re: Mathematica 3.01 is slower than Mathematica 3.0 on PowerMacs!
  • From: NOHAMcrose at c2.telstra-mm.net.au (Colin Rose)
  • Date: Tue, 25 Nov 1997 00:07:29 -0500
  • Organization: Theoretical Research Institute
  • Sender: owner-wri-mathgroup at wolfram.com

charles.bouldin at nist.gov (Charles Bouldin) wrote:

  > http://fampm201.tu-graz.ac.at/karl/timings30.html. If you look at
  > reference 89 on that page, you will see a report that Mathematica
3.01
  > is 15% slower than Mathematica 3.0. This is exactly the same result
  > that I reported to WRI within days of the release of 3.01.
  

Here are 2 examples of the slowdown, as measured using the standard Karl
Unterkofler's benchmark test:

                                    v3           v3.0.1
                                 _________      _________
  
  Timing[N[Pi, 13000]][[1]]      2.6  secs      3.65 secs

  Timing[10001!][[1]]            0.86 secs      1.73 secs


 [ Timings are on a PowerMac 8600/200/1meg L2 cache under OS8 
   with extensions ON. Switching extensions off improves performance 
   by about 5%. ]


An Oddity: is there really a slowdown ?  Or is Timing just wonky ?
_________


The above results are the times as measured and reported  by Karl
Unterkofler's benchmark test. This uses a Block structure which
prepares some calculations first.  One of these is DSolve. For
instance:

v3.0.1

  In[2]:=
  Block[{}, DSolve[D[y[x], {x, 2}] + y[x]*E^x == 0, y[x], x];
           {Timing[N[Pi, 13000]][[1]], Timing[10001!][[1]]}]

  Out[2]=
{  3.6 Second,1.75 Second}

__

Now, if this calculation is repeated (from a new kernel) but without the
DSolve[], the Timing results should NOT change. But just look what
happens:

v3.0.1

  In[2]:=
  Block[{}, {Timing[N[Pi, 13000]][[1]], Timing[10001!][[1]]}]

  Out[2]=
  {2.85 Second,1.06667 Second}


The timing results have changed dramatically, and they should NOT do so.

It is no longer clear whether or not there really is a timing slowdown
under v3.0.1. Unfortunately, the Timing function itself appears quite
wonky. If the timing fn is not reliable, then it questions the
suitability of benchmark tests under Mathematica, both across
platforms, and across versions of the same program, which is rather a
pity. 

Cheerio

Colin

-- 
Colin Rose 
tr(I) - Theoretical Research Institute
______________________________________ NOHAMcrose at c2.telstra-mm.net.au
http://www.usyd.edu.au/su/tri/



  • Prev by Date: Re: Assigning solutions found by FindRoot
  • Next by Date: Re: Interpolatingfunction
  • Previous by thread: Re: Mathematica 3.01 is slower than Mathematica 3.0 on PowerMacs!
  • Next by thread: Is Mathematica 3.0 book a good book/Manual? Re: Book recommendation