Re: Re: Re: why does not the Mathematica kernel seem to 'multi-task' between computations in different windows?

*To*: mathgroup at smc.vnet.net*Subject*: [mg69956] Re: [mg69892] Re: [mg69866] Re: why does not the Mathematica kernel seem to 'multi-task' between computations in different windows?*From*: "Chris Chiasson" <chris at chiasson.name>*Date*: Thu, 28 Sep 2006 06:15:30 -0400 (EDT)*References*: <200609271003.GAA00051@smc.vnet.net>

How about just buying one license with premier support? Then you can install Mathematica on a second computer and use it as a source of two remote kernels, in addition to the local computer's two kernels. On 9/27/06, Benedetto Bongiorno <bbongiorno at attglobal.net> wrote: > Mathgroup, > > I have been talking to Wolfram on the same issue. > I am in the process of purchasing a computer configuration that will > allow us to run > four notebooks simultaneously on a Windows XP 64 bit OS, using two > Opteron dual cores. > Wolfram has advised that one license of 5.2 will allow you to run two > notebooks simultaneously, > using one dual core processor. If we buy another license we can run two > additional notebooks simultaneously, > using second dual core processor. > Wolfram has made it clear all variables for each notebook's kernel is > confined to a core of the dual processor. > Wolfram's PersonalGrid appears to do the same thing with more functionality. > > Does anyone else have any experience in this area? > > Thank you, > Ben > > ben wrote: > > Hi, > > > > I suggest to check the manual about the difference between > > mathematica frontent (windows) and mathematica kernel (computation > > client): > > > > The frontend only displays your worksheet nicely, handles editing and > > sends > > commands to the kernel; its the kernel that does all the computation > > work. > > > > Now the point is: You can open several frontends which > > by default will all be linked to the same instance of the kernel. > > > > This has two surprising effects, > > > > 1. A kernel which is busy with a command from frontend no.1 is simply > > busy, it can not do computations for frontend no.2 in the same time > > > > 2. All variables are stored by the kernel, that is a variable defined > > in frontend no.1 > > is visible also in frontend no.2 > > > > Effect 2 makes clear why you cannot have multi-tasking: results would > > be not defined uniquely, since results from frontend no.2 can effect > > the state of the variables and thus computations in frontend no.1 and > > vice versa, and if you do not know which of two calculations running > > parallel finishes first you might end up in a whole mess. > > > > What's now the solution to your problem? > > > > Kernel->Kernel Configure Options allows you to add additional kernels > > (make them local for simplicity) > > Then by > > Kernel->Notebook's Kernel > > you can assign a unique kernel to each notebook. > > This will use up extra memory and maybe licences too. > > > > Hope that helps > > Ben > > > > Nasser Abbasi schrieb: > > > > > >> Hi > >> > >> Sometime I start some computation in one window which can take few minutes > >> to half an hour or more. > >> > >> It seems anything I type meanwhile in a second window does not get processed > >> until the first computation is completed. > >> > >> The computation does have 'Print[]' statements in it for debugging, so it is > >> not completely CPU bound, and I would think that one should be able to do > >> someone work in the second window meanwhile even if it might be slower to > >> respond. > >> > >> It seems that the Mathematica kernel can't be preempted at all once it > >> starts a computation, even if I/O calls are being made. > >> > >> Right now, once I start something, I can't use Mathematica at all until the > >> computation is over because the kernel is busy. (Except it seems I am able > >> to do File->Save ok while it is busy) > >> > >> Sometimes I start a second copy of Mathematica, but the limit is 2 instances > >> and I do not have lots of RAM. I also wonder if this limit should be > >> increased to say 5. > >> > >> I guess it is time for me to go buy a PC with those Intel new chips the > >> core2 with lots of RAM as I spend too much time now waiting for something to > >> complete. > >> > >> Nasser > >> > > > > > > > > > > -- http://chris.chiasson.name/

**References**:**Re: Re: why does not the Mathematica kernel seem to 'multi-task' between computations in different windows?***From:*Benedetto Bongiorno <bbongiorno@attglobal.net>