This paper describes an architecture for a dynamically heterogeneous processor architecture leveraging 3D stacking technology. Unlike prior work in the 2D plane, the extra dimension makes it possible to share resources at a fine granularity between vertically stacked cores. As a result, each core can grow or shrink resources, as needed by the code running on the core. This architecture, therefore, enables runtime customization of cores at a fine granularity and enables efficient execution at both high and low levels of thread parallelism. This architecture achieves performance gains from 9-41%, depending on the number of executing threads, and gains significant advantage in energy efficiency of up to 43%.

The increasing power dissipation of current processors and processor cores constrains design options, increases packaging and cooling costs, increases power delivery costs, and decreases reliability. Much research has been focused on decreasing average power dissipation, which most directly addresses cooling costs and reliability. However, much less has been done to decrease peak power, which most directly impacts the processor design, packaging, and power delivery. This research proposes a new architecture which provides a significant decrease in peak power with limited performance loss. It does this through the use of a highly adaptive processor. Many components of the processor can be configured at different levels, but because they are centrally controlled, the architecture can guarantee that they are never all configured maximally at the same time. This paper describes this adaptive processor and explores mechanisms for transitioning between allowed configurations to maximize performance within a peak power constraint. Such an architecture can cut peak power by 25% with less than 5% performance loss; among other advantages, this frees 5.3% of total core area used for decoupling capacitors.