Was this done with the G1 garbage collector brought in by Java 7 if not this is worth a new test.

It fixes a lot of problems that used to be introduced, and as long as you let it run wild with memory, and you are doing some parallelized work like everything real world, you should not see this problem.

There should be either no more, or less, stop the world.

There are a few things you can do to also avoid this problem all together:

The biggest improvement in speed vs memory will come from not passing primitive as function parameters. When you are doing this, you are passing-by-value, not passing-by-reference. If you wrap a bunch of ints to a function that you are using you can save a lot of allocation cycles.

Another good change that you can make would be an object pool. There is a really good and fast implementation in JMonkeyEngine/LWJGL. They have a low level, thread happy, object pool.