HuNT: Exploiting Heterogeneous PIM Devices to Design a 3-D Manycore Architecture for DNN Training

Processing-in-memory (PIM) architectures have emerged as an attractive computing paradigm for accelerating deep neural network (DNN) training and inferencing. However, a plethora of PIM devices, e.g., resistive random-access memory, ferroelectric field-effect transistor, phase change memory, MRAM, static random-access memory, exists and each of these devices offers advantages and drawbacks in terms of power, latency, area, and nonidealities. A heterogeneous architecture that combines the benefits of multiple devices in a single platform can enable energy-efficient and high-performance DNN training and inference. 3-D integration enables the design of such a heterogeneous architecture where multiple planar tiers consisting of different PIM devices can be integrated into a single platform. In this work, we propose the HuNT framework, which hunts for (finds) an optimal DNN neural layer mapping, and planar tier configurations for a 3-D heterogeneous architecture. Overall, our experimental results demonstrate that the HuNT-enabled 3-D heterogeneous architecture achieves up to $10 {\times }$ and $3.5 {\times }$ improvement with respect to the homogeneous and existing heterogeneous PIM-based architectures, respectively, in terms of energy-efficiency (TOPS/W). Similarly, the proposed HuNT-enabled architecture outperforms existing homogeneous and heterogeneous architectures by up to $8 {\times }$ and $2.4\times $ , respectively, in terms of compute-efficiency (TOPS/mm2) without compromising the final DNN accuracy.