I wrote a Java snippet, and run on the JRE 1.4.2. It consumed about 10 ~ 20ms
And I transformed the snippet in to JavaScript, and ran on Firefox and IE6, and it cost about 800~1800ms!

Some the JavaScript is something 180 times slower than the the Java codes, which is still interpreted language codes and not hardware codes! The efficiency is somewhat un-acceptable!

The efficiency of JavaScript strikes me hard! As I am wring something transform the Java codes into JavaScript codes! But the efficiency in such poor situation make the way ahead dim!