Java

The Java HotSpotTM Client and Server Virtual Machines

Documentation Contents
Two implementations of the Java virtual machine are available for J2SE 1.3:
Java HotSpotTM Client VM
Java HotSpot Server VM
The Solaris and Linux versions of J2SE 1.3 ship with both VM implementations. The Win32 version of J2SE 1.3 contains only the Java HotSpot Client VM. The Java HotSpot Server VM for Win32 platforms is available as a separate download from the Java HotSpot web site.

Some features of Java HotSpot technology, common to both VM implementations, are the following.

More information about Java HotSpot technology can be found in
Java HotSpot Architeture white paper
The Java HotSpot Server VM: The Solution for Reliable, Secure Performance for the Enterprise

The Java HotSpot Client VM

The Java HotSpot Client Virtual Machine* serves as a replacement for both the "classic" virtual machine and the Just-in-time (JIT) compilers used by previous versions of the Java 2 SDK to offer improved runtime performance for applications and applets. The Java HotSpot Client VM has been specially tuned to reduce application start-up time and memory footprint, making it particulary well suited for client environments.

On all platforms, the Java application launcher (the java utility) will use Java HotSpot Client VM by default when launching applications. For more information, see

Java HotSpot Server VM

The Java HotSpot Server VM is similar to the Java HotSpot Client VM, except that it has been specially tuned to maximize peak operating speed. It is intended for running long-running server applications, for which having the fastest possible operating speed is generally more important than having the fastest possible start-up time.

The Solaris and Linux versions of J2SE 1.3 ship with the Java HotSpot Server VM pre-installed. The Java HotSpot Server VM for Win32 platforms is available as a separate download from the Java HotSpot web site.

To invoke the Java HotSpot Server VM rather than the default Java HotSpot Client VM, use the -server option of the Java application launcher. For example:

java -server MyApp
*As used on this web site, the terms "Java virtual machine" or "JVM" mean a virtual machine for the Java platform.

Copyright © 1999, 2000 Sun Microsystems, Inc. All Rights Reserved.



Please send comments to: jdk-comments@eng.sun.com
Sun