Mechanical APDL Basic Analysis Guide - Ansys

Chapter 21: Memory Management and Configuration
The amount of physical memory (RAM) available on your computer is called real memory. The minimum
amount of real memory recommended for the ANSYS program varies from system to system and is listed
in your ANSYS, Inc. Installation Guide. It is helpful to understand the ANSYS memory-management scheme
and some frequently used terms concerning computer memory.
The following memory-management topics are available:
21.1. ANSYS Work and Swap Space Requirements
21.2. How ANSYS Uses its Work Space
21.3. How and When to Perform Memory Management
21.4. Using the Configuration File
21.5. Understanding ANSYS Memory Error Messages
To learn how to improve the performance of the ANSYS program, see "Using Shared-Memory ANSYS" in the
Advanced Analysis Techniques Guide.
21.1. ANSYS Work and Swap Space Requirements
The ANSYS program requires some space to reside in memory, plus additional work space. The ANSYS work
space defaults to 1 GB (1024 MB) for 64-bit machines, and 512 MB for 32-bit machines (Linux and Windows).
As shown in Figure 21.1 (p. 307), the total memory required for the ANSYS program usually exceeds the
amount of real memory available. The additional memory comes from system virtual memory, which is simply
a portion of the computer's hard disk used by the system to supplement physical memory. The disk space
used for system virtual memory is called swap space, and the file is called the swap file. On some systems it
is referred to as a page file. Other systems maintain multiple files, or even dedicated disk sectors to act as
virtual memory. The amount of swap space required for the ANSYS program depends on the amount of real
memory available, the size of the ANSYS executable, and the amount of ANSYS work space.
Figure 21.1 Comparing Available Memory
System virtual memory is used to satisfy additional ANSYS memory requirements.
21.2. How ANSYS Uses its Work Space
To understand how ANSYS uses its work space (the shaded portion in Figure 21.1 (p. 307)), you need to understand
its two components: database space and scratch space, as shown in Figure 21.2 (p. 308). Database
space is used to work with the ANSYS database (model geometry, material properties, loads, etc.). Scratch
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