From: Sebastian Sardina (ssardina@cs.toronto.edu)
Date: Thu 05 Dec 2002 - 02:15:01 CET
On Wed, 2002-12-04 at 19:42, Adrian Holzwarth wrote: > (summary: > multi-threading slower than single-thread? > multi-threading 5.12 slower than 5.11? ) > > I've to regret that I might have missed some things. Was there already > the question about the hardware being used? I'd guess that a swi-prolog > with multi-threading running on a single-cpu-machine cannot run faster > than a single threaded version. If you want to split the work to be done Indeed I do not expect the multi-threading version to run faster, but just equivalent if I do not use multi-threads at all. > you need a second (or more :)) cpu to bother. Worse, otherwise you are > creating overhead with dividing the work into pieces and managing the > mess. And the lonesome single CPU has to do *all* the computing anyway, > successive. I understand that, but say you don't do anything fancy: you just run a regluar Prolog program like the 9-queens example. So the problem is: why the multi-threading version of Prolog running a single thread is slower than the single-thread version of Prolog running the same single thread program? > Another blind guess for the performance loss 5.11 --> 5.12. If (and only > if) you are using a single CPU, you are using the program not the way it > was intended to be used - and an improvement in multithreading may show > up that way here in a loss of speed. > > Again, I've to repeat that I might have missed some things. But since > I'm listening to the list for a long time without doing any good, it is > time that I at least *try* to solve other people's problems. ;) yes, it's good to see the list quite active.! ;-) > Adrian > > -- > Computers are not intelligent. They only think they are. well, that may be enough (or even too much) to qualify... ;-) Cheers Sebastian > > > ---------------- > * To UNSUBSCRIBE, please use the HTML form at > > http://www.swi-prolog.org/mailinglist.html > > or send mail to prolog-request@swi.psy.uva.nl using the Subject: "unsubscribe" > (without the quotes) and *no* message body. > > ** An ARCHIVE of this list is maintained at > > http://hcs.science.uva.nl/projects/SWI-Prolog/mailinglist/archive/ > >