Mechanical APDL Basic Analysis Guide - Ansys

Figure 21.4 Dividing Work Space
ANSYS Work Space = 512 MB
256 MB 256 MB
Database Space Scratch Space
128 MB 384 MB
Database Space Scratch Space
384 MB 128 MB
Database Space Scratch Space
Allocating more database space leaves less for scratch space, and vice versa.
To allocate more or less database space, use the database space entry option (-db) while starting up the
program, either on the ANSYS launcher or on the ANSYS execution command. Although all of the above
diagrams correspond to a -m value of 512 MB, their -db values correspond to 256, 128 and 384 MB, respectively.
You may need to divide work space differently in these situations:
21.3.3. Changing Database Space From the Default
• When you are about to solve a large model or a computationally intensive analysis, or for large jobs
with memory requirements close to your system's limits. For these situations, run the solution phase as
a batch job with minimal -db space (usually 64 MB). Note that to insure enough scratch space, you
should use a negative value (for example, -db -64) to prevent ANSYS from allocating additional memory
required to hold the database. By reducing the amount of database space, you will increase the scratch
space, allowing more memory for solution. Before postprocessing, increase the -db and resume the
jobname.db file and run interactively.
• On 32-bit systems, when you see the message about the page file (Jobname.PAGE) being written.
This means that the database space is too small for your model, so you should increase it. Be aware,
though, that increasing the database space decreases scratch space, so you also may want to increase
total work space if you plan to do memory-intensive operations (Boolean operations, load case combinations,
etc.).
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