Solution Process

There are two parts to the Radioss simulation, the Starter and Engine. The Starter is an input data check and must successfully complete without errors before the simulation can be completed in the Engine.

Starter and Engine

The Radioss Starter takes as input the model or commonly called Starter input file runname_0000.rad and creates the Starter output file runname_0000.out. The Radioss Starter is responsible for checking the model consistency and reporting any errors or warnings in the output file. If there are no errors in the model, the Radioss Starter creates initial restart file(s), runname_0000_CPU#.rst. There is one restart file created for each SPMD MPI domain requested for the solution.

The second part of the Radioss computation is called the Radioss Engine. The Radioss Engine takes as input the Radioss Engine file, runname_0001.rad and the initial restart file(s) created by the Radioss Starter. The Radioss Engine files describes the solution control and output for the simulation. While the Radioss Engine is running, an Engine output file, runname_0001.out, is created which contains statistics about the simulation including time, time step, current system energeies, energy error, and mass error.


Figure 1. Radioss Calculation Process when a Single MPI Domain is Used

Memory and Disk Requirements

Memory is allocated automatically by the Radioss Starter and the amount used is listed in the Starter output file.
STARTER MEMORY USAGE       1486 MB
Next the Starter gives a memory estimation and restart file size for every MPI process.
     LOCAL ENGINE STORAGE EVALUATION FOR SPMD PROCESSOR     1
     --------------------------------------------------------
        MEMORY USED FOR REALS           80 MB
        MEMORY USED FOR INTEGERS        35 MB
        TOTAL MEMORY EVALUATION        115 MB
        RESTART FILE SIZE     60091KB
...
     LOCAL ENGINE STORAGE EVALUATION FOR SPMD PROCESSOR    18
     --------------------------------------------------------
        MEMORY USED FOR REALS           83 MB
        MEMORY USED FOR INTEGERS        38 MB
        TOTAL MEMORY EVALUATION        122 MB

        RESTART FILE SIZE     63349KB
After the Radioss Engine is done running, the Engine output file contains details about actual memory and disk space used by a simulation.
                   ** MEMORY USAGE STATISTICS **

 TOTAL MEMORY USED .........................:    10284 MB
 MAXIMUM MEMORY PER PROCESSOR...............:      605 MB
 MINIMUM MEMORY PER PROCESSOR...............:      562 MB
 AVERAGE MEMORY PER PROCESSOR...............:      571 MB


                   ** DISK USAGE STATISTICS **

 TOTAL DISK SPACE USED .....................:    1421485 KB
 ANIMATION/TH/OUTP SIZE ....................:     200950 KB
 RESTART FILE SIZE .........................:    1220535 KB