IBM first announced its 3D chip stacking concept in April last year. The idea is to put chips and memory devices on top of one another like a silicon sandwich, rather than arrange them side by side. This will supposedly reduce wire delay by a thousand times, improve CPU efficiency, and significantly reduce total power consumption. Until now, however, thermal dissipation has been a major obstacle for the technology as every layer in a 3D chip makes it more difficult to remove heat emanating from the lower levels.
We're still a long way off from three-dimensional processors but IBM’s prototyped water-cooling solution seems like a big step in the right direction. The company hopes to commercialize such stacks for its multi-core servers in about five to ten years.