OS should dynamically switch core for each process. Yet it is possible to tell os which core should be used. Google for "cpu affinity" should give the some examples.
On Mon, 08 Sep 2008, Devon McCormick wrote: > It seems to me that the OS is smart enough to put new processing on the > less-loaded core. I find the advantage of two cores as opposed to one is > that while I'm running a CPU-intensive J-app, I can still do other work with > no noticeable slow-down. When I run the same J-app on a single-core > machine, it becomes very hard to use for anything else. > > I'm guessing that you could fire up three independent J-apps on a quad-core > and that each would run on its own core, leaving the fourth free to do > important things like read Slashdot and respond to the J-forum. However, I > lack a machine on which to test this hypothesis. > > On 9/8/08, Alex Rufon <[EMAIL PROTECTED]> wrote: > > > > I was able to do what Devon described accidentally. I built a windows > > service which spawns an instance of J for each client connection. The > > machine was a Compaq server with multiple CPU's running on Windows 2000 > > Advance Server. I never really intended it to run J on multiple-CPU's but it > > does. :) > > > > Still, I don't do interprocess communication and each J session is atomic > > with all its data and script. Oh, I did some observation and the OS > > assigning which CPU is I believe arbitrary ... although the first few > > instances of J would always run on CPU-0. > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of Devon McCormick > > Sent: Monday, September 08, 2008 7:20 PM > > To: Chat forum > > Subject: Re: [Jchat] parallel processing in J > > > > Hi - > > > > I don't think this is a J issue. I've been able to make use of both cores > > on my dual-core machine by running separate instances of J - it looks like > > the OS handles this. Try running CPU-intensive tasks on multiple versions > > of J simultaneously. > > > > Regards, > > > > Devon > > > > On 9/8/08, Matthew Brand <[EMAIL PROTECTED]> wrote: > > > > > > Hi All, > > > > > > I don't know much about the subject but when I look at task manager, the > > > CPU > > > usage only goes up to 25% on the four core processsor. Is there a > > > configuration that makes J use all the cores? > > > > > > As I say, I don't know much about it but does this mean that it should be > > > possible: > > > > > > >From http://en.wikipedia.org/wiki/J_(programming_language)< > > > http://en.wikipedia.org/wiki/J_(programming_language>: > > > "Being an array programming > > > language<http://en.wikipedia.org/wiki/Array_programming_language>, > > > J is very terse and powerful, and is most suited to > > > mathematical<http://en.wikipedia.org/wiki/Mathematical>and > > > statistical <http://en.wikipedia.org/wiki/Statistical> programming, > > > especially when performing operations on > > > matrices<http://en.wikipedia.org/wiki/Matrix_(mathematics)>. > > > J is a MIMD <http://en.wikipedia.org/wiki/MIMD> language." > > > See: > > > http://en.wikipedia.org/wiki/MIMD > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > > > > > > -- > > Devon McCormick, CFA > > ^me^ at acm. > > org is my > > preferred e-mail > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > Devon McCormick, CFA > ^me^ at acm. > org is my > preferred e-mail > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
