Thermal requirements in future 3D processors

This paper reports on a study in which the projected thermal load of future 3D optimized embedded computers was explored. The approach taken was to project the performance, power consumption and area of a reasonably power-efficient 7 nm, 6672 core baseline conventionally packaged (“2D”) design, and 3D alternatives to this design. The 3D alternatives have improved power efficiency over the baseline 2D design, due to their reduced interconnect power consumptions and reduced processing overhead. The most efficient set of designs use more aggressive 3D-specific strategies to increase power efficiency at the expense of increased heat flux. The most efficient design is 38% more power efficient than the baseline 2D design, but has 13x the heat flux of that design. The value of that heat flux was 5.4 W/mm². Further optimizations increase the thermal flux even further. Specifically creating architecture optimized to floating point operations, increases the heat flux to 17 W/mm² while improving the computing efficiency by another 2x.