From: Peter Hickman Date: 2006-08-05T00:32:32+09:00 Subject: Re: For performance, write it in C - Part 3, Source code now available Isaac Gouy wrote: > Peter Hickman wrote: > >> Time for another update. >> >> Isaac Gouy provided a Java implementation based on mine (ie still pre >> computes the tables in Perl) that brought the times down to sub 9 seconds. >> >> real 0m8.966s >> user 0m5.815s >> sys 0m1.488s >> > > sub 9 seconds? > 7.3s > "real" is elapsed time, which includes all those other processes that > grabbed CPU after you gave the time command. > > > > This is a good point but in all the posts where I have mentioned the time taken I have used the real time (which is the best case from 10 runs - except for the first Perl version) all the way back to the first and fourth versions in Perl (473 and 12 minutes). However it does not affect the ordering except to push my improved C version ahead of William James' revised Ocaml version by just 0.029 of a second. This late in the proceedings it would only confuse the issue to start saying that the first Perl version ran in 251 minutes when 473 minutes has been mentioned several times. Besides now that we are getting into such short times for the Ocaml and C versions the difference between real and user + sys is sub second and it is becoming harder to say that one is significantly faster then the other. One more run of William James' program and it might make up that 0.029 of a second difference. Perhaps stepping up to a 6 x 6 grid would allow more meaningful timings?