That depends on your memory usage. There is an awkward range (32GB - 48GB) where the increase in heap size does not give you a proportional increase in availabl

That depends on your memory usage. There is an awkward range (32GB - 48GB) where the increase in heap size does not give you a proportional increase in available memory because of the doubling of references. That is where you're better off running multiple instances. But for heaps bigger than 48GB running a single jvm is more efficient.