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-   -   NuTCRACKER problem (http://www.cfd-online.com/Forums/cfx/18294-nutcracker-problem.html)

Zoltan Turzo December 14, 1999 11:35

NuTCRACKER problem
 
I have CFX4.2 running on a Windows NT 4.0 workstation. In the Application Log of the Event viewer i have got the following event all the time

Configuration information not found. Using default limits for system resources. File: nckernl.c Line Number: 315

What does it mean exactly: Using default limits for system resources.

Does It mean that when i am using cfx it does not use all of my 128 MB of memory?

John C. Chien December 14, 1999 13:42

Re: NuTCRACKER problem
 
(1). Portion of the memory is used by the Windows functions so that you can interact with the computer.(2). I think, commercial code is not just one .exe file, the whole package must have many separate modules(programs) in it. And when each module is loaded into the momory when you activate it, it will require some memory space to work in the multi-tasking environment.(3). Apparently, each module's memory requirement is not fixed, it depends on the mesh size. If the default memory size specified for that particular module (program) is not enough (out of the reserved memory), you need to change the default setting of the memory size for that module in order for it to work. (this depends on how the program is written.) (4). For fixed size program, one can always figure out the total memory required for the program, because it rarely change much for any application (traditional Fortran program with fixed dimensioned arrays). But when the program memory size is dynamically allocated, it can run out of menory during execution. (5). So, I think, this is why the vendor limit the size of each module inside the program package in the default setting file. (that is try to make sure you can run through every module when the program is activated by the user.) Without such management, pretty soon, you will run out of memory later in the process when trying to execute a module in the package. (5). In the DOS environment, only one program can execute and it has the full control of the machine. But even then, the DOS functions also must reside in the memory in order to serve the application program. So, your application can only use the rest of the free memory, not all of the installed memory. (6). If you are the only person running the workstation all the time, you can try to increase the mesh size to the limit such that each module will be at its maximum size to serve the application. After all the default limits have been set to the maximum allowable size, you should have no problem later in running a smaller job. But, if you are sharing the workstation with other aplications, then it is a good idea to use the memory as required. (7). The above answer is not specific to the particular code.


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