Perceivably Slow

I installed the new version of the Java SDK, 1.6 (Mustang), at work recently and was surprised by the performance change. Looking at David Dagastine's discussion on of JDK performance, one would think that performance should and would be better.

I was grossly underwhelmed.

After installing the new SDK, I ran an install of Tomcat 5.5. My server start-up times were running between 5 and 9 seconds. Given that I start and stop the server many times in an hour[1], I really thought it would be great to reduce this time. The startup time with Mustang jumped to between 25 and 35 seconds.

Once it had started up, the performance seemed comparable to the 1.5 VM (if not better - I'm sure that it's here where Dagastine's numbers are accurate). That start up time is, however, miserable. It effects the perceived performance of the whole experience[2].

This startup performance force the designers of applications to add little things to their applications, like splash screens, startup info, etc. This will increase the perceived performance of the application by giving the illusion of things happening.


[1] This is due to the fact the file I'm using is loaded through a servlet. Due to the way that ClassLoader.getResourceAsStream() loads the stream into memory. Only restarting the VM allows me to reload the changes.