JRuby 1.1.3 Performance

It's been awhile since I did a post with pretty graphs and meaningless micro-benchmarks. I am using the latest version of JRuby, 1.1.3 on a new project. I knew from some correspondence with Charlie Nutter that the performance bug that I had encountered previously were believed to be solved. I said believed because he had not had a chance to test on the IBM J9 JVM that (along with some other JVMs) exhibited the performance problem. Actually this was fixed in 1.1.2, and I should have tested things then, but didn't get around to it until now. I decided to throw in the latest beta of JDK 1.6 update 10, the magical JDK for The Rest of Us. Here is the purrty chart:


The good news is that even with the J9 JVM, JRuby outperforms native Ruby, at least on this mathematical algorithm. This was not the case prior, so the JRuby fixes have really helped. In fact, if I look at the last data point (x=100), the code executed in less than half the time it took previously with the only change being the JRuby 1.1.3 instead of 1.1. I could describe the source of the bug, but you are much better off reading Charlie's description.