Installing › Installing DevTest Server and Post-Installation › Post-Installation › Calculate Simulator Instances

Calculate Simulator Instances

To calculate the number of instances for a specific simulator, do the following analysis:

1. Start DevTest Workstation, select the registry, and log in. Note the memory usage from Help, DevTest Runtime Info.
2. Run the test suite locally and note the memory usage from Help, DevTest Runtime Info.
3. Take the difference between the memory usage in step 2 and step 1.
4. Multiply your available RAM by 60 percent.
5. Divide the available RAM in step 4 by the memory usage in step 3.

The result of step 5 is a good starting estimate of the number of virtual users (instances) that you need configured in your simulator server.

If the coordinator server and the registry both run on the same server as the simulator server, then multiply available RAM by 40 percent. Use 40 percent instead of 60 percent because the coordinator server collects all reports and metrics and therefore consumes RAM.

This technique provides a starting point. To get to the correct number of instances for each simulator, use several iterations and other intuitive methods.

Note: You can set the number of concurrent instances for a simulator with a command-line option. Open a command prompt, navigate to the LISA_HOME\bin directory, and type simulator --help for details.