thanks On Nov 6, 6:04 pm, Andy Fingerhut <andy.finger...@gmail.com> wrote: > The amount of work in each element of the pmap is so small that the overhead > per element is dominating the CPU usage, e.g. overhead like constructing a > future for each element of the collection you are mapping over. Try a test > case where the computation being done in the function you supply to map is a > lot more than inc. > > Note that total CPU time for pmap will always have some extra overhead above > the corresponding map - it is recommended to use it when that extra overhead > is small compared to the total computation time required. > > Andy > > Sent from my iPhone > > On Nov 6, 2010, at 4:57 AM, philip schwarz > <philip.johann.schw...@googlemail.com> wrote: > > > > > > > > > Hi all, > > > be gentle please: I have only just started using clojure. > > > I run the following on an Intel Core 2 Duo CPU (starting clojure with > > "java -Xms1000m -Xmx1000m -jar clojure.jar"): > > > user=> (time (nth (doall (map inc (range 10000000))) 9999999)) > > "Elapsed time: 5944.068355 msecs" > > 10000000 > > > user=> (time (nth (doall (pmap inc (range 10000000))) 9999999)) > > "Elapsed time: 108837.451146 msecs" > > 10000000 > > > I was expecting pmap to take less time then map, instead it took much > > much longer. > > > Any thoughts? > > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to clojure@googlegroups.com > > Note that posts from new members are moderated - please be patient with > > your first post. > > To unsubscribe from this group, send email to > > clojure+unsubscr...@googlegroups.com > > For more options, visit this group at > >http://groups.google.com/group/clojure?hl=en
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