After that you discover it's a NUMA machine, you have a lot of inter-cpu communication and curse you have no GC. Why? Because you bottleneck inter-cpu communica

After that you discover it's a NUMA machine, you have a lot of inter-cpu communication and curse you have no GC. Why? Because you bottleneck inter-cpu communication so easily with object synchronization. With GC quite a bit of it can be avoided. If Java just didn't need to allocate each damn small value object (think struct) separately, I think it'd be a lot better with large heaps. Array of 1000 non-elementary values could be just one allocation, not 1001. That'd also be 1000 times faster to garbage collect.