I need to use a java library that uses native code requiring a 32-bit jvm. I have 64-bit windows with 64-bit eclipse installed with 64-bit JDK7. In order to develop with it, do I need to have 32-bit JDK? Or would the JRE suffice? If it is possible to install both, what is the naming convention you use for the installation directory for the 32-bit jre or jdk? I have heard rumors there is a performance hit on virtual memory if both are installed, is this true?