OpenJDK 1.6 vs OracleJRE 1.6 and OpenJDK 1.7
While absolute speed is an interesting topic, relative JVM performances is an even interesting thing: by comparing the relative speed of two JVM implementations, we have an at-a-glance reference point to understand how the two software stacks evolved over time.
First, lets compare the OpenJVM 1.6 stack against Oracle 1.6 one.
As you can see, the Oracle 1.6 stack is almost always faster the the open 1.6 one, save for the startup time and the scimark.large test.
Is the OpenJDK 1.7 stack an improvement over the old 1.6 one?
Yes, it is: while 1.6 remain faster on startup and scimark.large, the new 1.7 stack wins the other tests.