Proteus: Enabling High-Performance Processing-Using-DRAM with Dynamic Bit-Precision, Adaptive Data Representation, and Flexible Arithmetic

TL;DR

Proteus introduces a dynamic, data-aware framework for processing-using-DRAM that reduces latency and energy consumption by adapting bit-precision, data representation, and execution strategies based on data characteristics.

Contribution

Proteus is the first hardware framework to dynamically optimize PUD operations by adjusting bit-precision and data representation, improving efficiency and performance.

Findings

Reduces PUD operation latency significantly.

Improves energy efficiency through dynamic bit-precision adjustment.

Enhances throughput by concurrent execution across multiple DRAM arrays.

Abstract

Processing-using-DRAM (PUD) is a paradigm where the analog operational properties of DRAM are used to perform bulk logic operations. While PUD promises high throughput at low energy and area cost, we uncover three limitations of existing PUD approaches that lead to significant inefficiencies: (i) static data representation, i.e., two's complement with fixed bit-precision, leading to unnecessary computation over useless (i.e., inconsequential) data; (ii) support for only throughput-oriented execution, where the high latency of individual PUD operations can only be hidden in the presence of bulk data-level parallelism; and (iii) high latency for high-precision (e.g., 32-bit) operations. To address these issues, we propose Proteus, the first hardware framework that addresses the high execution latency of bulk bitwise PUD operations by implementing a data-aware runtime engine for PUD. Proteus reduces the latency of PUD operations in three different ways: (i) Proteus dynamically reduces the bit-precision (and thus the latency and energy consumption) of PUD operations by exploiting narrow values (i.e., values with many leading zeros or ones); (ii) Proteus concurrently executes independent in-DRAM primitives belonging to a single PUD operation across multiple DRAM arrays; (iii) Proteus chooses and uses the most appropriate data representation and arithmetic algorithm implementation for a given PUD instruction transparently to the programmer.