You are not wrong, but note that "memory" is not just RAM, it is also the disk space that is needed for swapping pages in and out. So, the required address spac

You are not wrong, but note that "memory" is not just RAM, it is also the disk space that is needed for swapping pages in and out. So, the required address space you keep referring to is not some cost-less abstraction; rather, it does in fact correspond to some physical bytes - no matter where they reside at a given particular moment, and it looks like the thing does actually need more than 4G of those.