PIMSys: A Virtual Prototype for Processing in Memory

Data-driven applications are increasingly central to our information technology society, propelled by AI techniques reshaping various sectors of our economy. Despite their transformative potential, these applications demand immense data processing, leading to significant energy consumption primarily in communication and data storage rather than computation. The concept of processing-in-memory (PIM) offers a solution by processing data within memory, reducing energy overheads associated with data transfer. PIM has been an enduring idea, with recent advancements in DRAM test chips integrating PIM functionality, indicating potential market adoption. This paper introduces a virtual prototype of Samsung’s PIM-HBM architecture, leveraging open-source tools like gem5 and DRAMSys, along with a custom Rust software library facilitating easy utilization of PIM functionality. Key contributions include the first gem5 based full-system simulation of PIM-HBM, experimental validation of the virtual platform with benchmarks, and the development of a Rust library enabling PIM functionality at the software level. Our benchmarks evaluated speedup for PIM in the range of 6.0 × to 17.5 × compared to a respective non-PIM system for different memory-bound workloads.