GPUs and other big AI chips just can’t get enough memory. Today’s data center computers stack DRAM 12 dies high. But as memory makers try to build higher stacks to pack in more bits and bandwidth, experts worry this high bandwidth-memory (HBM) will trap enough heat to cook itself into oblivion. That will be especially true if GPU makers choose to start stacking HBM atop their already hot processors to boost bandwidth instead of placing them beside the processor.Engineers around the world are working on an alternative: Instead of stacking the DRAM dies atop each other, why not stack them side by side? In that way they hope to turn a future towering inferno into a cube of cool silicon fins.Last month at the IEEE VLSI Symposium, two research groups showed different paths to such a chip. One p
