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
