# JDK 1.1 Performance Enhancements

For JDK performance measurements, see Performance Measurements on the JavaSoft website.

- Interpreter Loop in Assembly Code on Win32 and Solaris/SPARC
  Since portions of the Java VM have been rewritten in assembly language, the resulting VM now runs up to five times faster on certain operations.
- Non-Continuous Heap Support for Mac
  Improved memory usage on Macintosh computers enables Java to run more smoothly with other applications.
- Monitor Speedups
  Synchronized methods enable operations to run more quickly and efficiently.
- Garbage Collection of Classes
  This enhancement automatically discards unused classes. Improved overall VM memory usage enables Java to operate more efficiently, and with less memory.
- AWT Peer Class Re-Write for Win32
  To achieve higher performance, AWT peer native classes have been completely rewritten to be hosted running on top of Win32.
- JAR (Java Archive) bundling of resources for a single HTTP transaction
  JAR is a new JDK 1.1 platform-independent file format that aggregates many files into one. Java applets and their requisite components--such as class files, images and sounds--can be bundled into a compressed JAR file and downloaded to a browser in a single HTTP transaction to reduce download time. In addition, applet authors can digitally sign individual entries in a JAR file to authenticate their origin.