30.13 Memory and CPU Usage

There are two types of system reporting, which are accessed using the text interface, that can be performed while running ANSYS FLUENT processes:

• Reporting the status of each of the ANSYS FLUENT processes, including memory and CPU usage ( report/system/proc-stats).

• Reporting the status of the machines where ANSYS FLUENT processes have been spawned, including memory and CPU status ( report/system/sys-stats).

Note that the report/system/sys-stats text command is only applicable for Windows (ntx86 and win64) and Linux (lnamd64, lns86, and lnia64) platforms. Similarly, the report/system/proc-stats text command is only applicable for Windows, Linux, and AIX platforms.

The type of information you can expect to see printed to the console when running in parallel, using the report/system/proc-stats text command, is

------------------------------------------------------------------------------
       | Mem Usage (MB)                   | CPU Time Usage (Seconds)         
ID     | Current    Peak       Page Fault | User         Kernel   Elapsed      
------------------------------------------------------------------------------
host   | 31.2422    285.242    9.439e+004 | 34.4531      1.90625  269.593      
n0     | 525.949    743.438    3.933e+005 | 20.7656      3.70313  264.406      
n1     | 516.063    737.438    3.867e+005 | 84.2813      166.328  264.437      
------------------------------------------------------------------------------
Total  | 1073.25    1766.12    8.744e+005 | 139.5        171.938  -            
------------------------------------------------------------------------------

Under Mem Usage (MB)

Current   is the virtual memory usage at this very moment.

Peak   is the peak virtual memory usage.

Page Fault   is the number of page faults that have occurred.

Under CPU Time Usage (Seconds):

User   is the CPU time used by user processes.

Kernel   is the CPU time used by system kernel.

Elapsed   is the wall clock time elapsed since the process startup.

When using the report/system/sys-stats text command, where ANSYS FLUENT processes have been spawned on five machines, the following results are displayed:

------------------------------------------------------------------------------
                | CPU                              | System Mem (MB)                  
Hostname        | Number   Clock (MHz)  Load       | Total        Available  
------------------------------------------------------------------------------
deva01          | 2        2211.38      0.2        | 32205.2      31479      
deva03          | 2        2211.34      0          | 32205.2      21560.4    
deva04          | 2        2211.34      0          | 16093.7      12075.8    
deva05          | 2        2211.34      0          | 16093.7      14624.5    
deva06          | 2        2211.34      0.07       | 16093.7      12095.4    
------------------------------------------------------------------------------
Total           | 10       -            -          | 112691       91835.2    
------------------------------------------------------------------------------

Under CPU

Number   is the number of processors on the machine.

Clock   is the processor speed.

Load   is the work load on the machine.

Under System Mem (MB)

Total   is the total system memory on the machine.

Available   is the available system memory on the machine.

You can use the two commands together to plan ANSYS FLUENT jobs and machines accordingly. It may also be useful to diagnose performance problems.