Amdahl's Law in the 3-D Era
In this paper, the authors study the effect of 3-D Chip Multi-Processor (CMP) integration on Amdahl's law. The influence of vertical communication and thermal gradients on CMP performance and scalability is studied from Amdahl's law perspective. They find that a fast vertical connectivity enabled by 3-D implementation shifts the optimum CMP configuration towards the larger number of lighter cores, thus improving CMP scalability relative to 2-D implementation. However, they also show that a high level of parallelism may lead to high peak temperatures, even in smaller scale 3-D CMPs, thus limiting 3-D CMP scalability and calling for different, non-CMP architectures.