Well given Apple doesn't appear to be gaining a latency advantage from their ram on package the jury seems to still be out on that theory. OTOH, the trend has

Well given Apple doesn't appear to be gaining a latency advantage from their ram on package the jury seems to still be out on that theory. OTOH, the trend has been to put HBM/edram/etc on package for a while. Various intel/etc products have done that, which provides a fast tier of memory that you put in a local NUMA domain. Then put the actual DRAM in its own domain. The problem so far is that strategy doesn't actually work well for most applications because they aren't sufficiently NUMA aware to take advantage of it. Instead what ends up happening is the "fast" ram ends up being a LLC tier. It all ends up sorta being a physics thing though, it seems as you increase capacity, distance tends to grow as well. Meaning that there will be a limit to how much RAM they can toss on package and still gain a latency advantage over just soldering it to the board.