The 64-bit JVM defaults to using slightly less than half the physical memory available. Increasing the percentage of physical memory higher than the default has NOT been tested for accuracy during a load test. Instead, we recommend adding more physical memory or splitting the repository into multiple files.
If you wish to experiment yourself, you can edit the configuration file. Navigate to where you installed Web Performance Load Tester, which is usually C: Program FilesWeb Performance Tester.
Right click on the file "webperformance" and edit using Notepad.
Add the line "-Xmx" to the bottom of the file, appending the amount of memory you'd like Java to use. For example, to force it to utilize 6 gigabytes of memory, the line would be "-Xmx6g":
