Under stress test, OpenClinica has performed well with the following JVM settings: 

Please click the Java Options tab described in the ‘Configure Tomcat’ section and add the following 

 -XX:+UseParallelGC
-XX:ParallelGCThreads=n
-XX:MaxPermSize=180m
-XX:+CMSClassUnloadingEnabled

 On Java Console use ‘Maximum Pool Size’ to 1280.

Please note that the bare minimum ram requirement is 1280 MB of memory for these settings, so the CPU is expected to have much higher RAM available.

Where n is the number of cores of your CPU.  There should be no spaces before or after each entry, Also each entry should be in a new line. The MaxPermSize value depends on the number of war files that you are deploying. For instance, if you deploy web and web servics, XX:MaxPermSize should be set to 360m. 

 -XX:ParallelGCThreads = # of cores of your CPU, as long as the number of processors on your CPU are lesser than 8.   The Window should look like this for a 4 core processor:

After the above settings have been applied, start Tomcat