Re: Re: "No more memory available" -- a recurring problem
- To: mathgroup at smc.vnet.net
- Subject: [mg68401] Re: Re: [mg68356] "No more memory available" -- a recurring problem
- From: "Charlie Brummitt" <cbrummitt at wisc.edu>
- Date: Wed, 2 Aug 2006 15:20:55 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
J=E1nos, Thanks for the advice. I'm not really sure how to interpret the information in the terminal window, so I have attached screenshots of it at various stages (see the names of the images). I have attached them in chronological order. [Attachments are not allowed - please contact the author to get them - moderator] It seems to me that Mathematica is only being allocated 50% of the CPU and 100 megabytes of RAM! When I did the "top" on my 12" PowerBook, 93% of the CPU was being used while Mathematica was running my code. How do I change this on my 15" MacBook Pro? My 12" PowerBook is able to run this code overnight and very rarely gives the "ran out of memory" error message. I would like to be able to run my code overnight on my MacBook Pro, but it can only run for 5 to 10 minutes before it runs out of memory and completely halts. Thus I can't "set it and leave it"; instead, I must always be at my computer to restart the calculation every 5 to 10 minutes. Any suggestions? Thanks for all your help, J=E1nos. Charlie On 8/2/06, J=E1nos <janos.lobb at yale.edu> wrote: > > On Aug 2, 2006, at 5:24 AM, Charlie Brummitt wrote: > > > I keep getting the following error message while running a search > > of many PDE's: > > > > "No more memory available. > > Mathematica kernel has shut down. > > Try quitting other applications and then retry." > > > > This message is becoming so common that it is crippling my research > > project, which is to find the simplest PDE with one quadratic > > nonlinearity that is chaotic. > > > > I have Googled and searched the Mathgroup archives for help, and I > > employed the following fixes: > > > > --CODE & SOFTWARE-- > > 1) Share[] -- does not help because my code rarely has common elements > > that Share[] could consolidate. > > > > 2) I used Module[] and made as many variables local as possible. I > > eliminated extra variables and functions in addition to adding Clear[] > > in several places in the code to clear variables that are no longer > > needed. > > > > 3) I streamlined and optimized the code in general, and I made the > > routines as simple and least data-intensive as possible. > > > > 4) I never have any other applications open when running Mathematica. > > (Unfortunately, closing other applications is the only suggestion that > > Mathematica provides in the "out of memory" error message.) > > > > 5) I should note that I run the latest version of Mathematica > > (5.2.2.0). > > > > --HARDWARE-- > > 1) I upgraded from a 12" PowerBook to a 15" MacBook Pro. This computer > > has an 2.16 GHz Intel Core Duo processor. > > > > 2) I upgraded the RAM on this new computer from 1 GB to 2 GB. > > > > 3) I now have much more free hard drive space (20 GB) in case > > Mathematica needs to use virtual memory. In addition, this hard drive > > is 7200 rpm versus the standard 5400 rpm. > > > > > > I have been using functions like MemoryInUse[] and On[MemoryConserve] > > to monitor the use of memory. I almost always find that I am only > > using a few megabytes at a time (usually 5-10 MB, sometimes as high as > > 100 or once 1000 after a large computation). However, despite finding > > that I usually use only a few megabytes during my computations, I > > often get the above "out of memory" error message, and I can never > > figure out why and how much memory was needed in that particular > > computation. > > > > > > Some questions: > > 1) How can I tell whether Mathematica is using virtual memory or not? > > It seems to me that it is not. I have 20 GB of hard drive space free > > and it never seems to use it. Why should I ever run out of memory if I > > have 20 GB free in case it needs more memory than my RAM provides? > > > > 2) Is there a way to determine how much of my 2 GB of RAM are > > allocated to Mathematica? Can I increase how much RAM Mathematica can > > access? > > > > Thanks in advance for any help you may be able to provide! I greatly > > appreciate it. If you need more information on my code or the > > computations I am doing, I would be happy to provide it. > > > > Regards, > > Charlie > > If you open a Terminal window on the side and type "top" and hit > return and start up your application, what do You see for real memory > usage for the kernel and the front end from top? > > J=E1nos