Training machine learning (ML) algorithms is a computationally intensive
process, which is frequently memory-bound due to repeatedly accessing large
training datasets. As a result, processor-centric systems (e.g., CPU, GPU)
suffer from costly data movement between memory units and processing units,
which consumes large amounts of energy and execution cycles. Memory-centric
computing systems, i.e., with processing-in-memory (PIM) capabilities, can
alleviate this data movement bottleneck.
Our goal is to understand the potential of modern general-purpose PIM
architectures to accelerate ML training. To do so, we (1) implement several
representative classic ML algorithms (namely, linear regression, logistic
regression, decision tree, K-Means clustering) on a real-world general-purpose
PIM architecture, (2) rigorously evaluate and characterize them in terms of
accuracy, performance and scaling, and (3) compare to their counterpart
implementations on CPU and GPU. Our evaluation on a real memory-centric
computing system with more than 2500 PIM cores shows that general-purpose PIM
architectures can greatly accelerate memory-bound ML workloads, when the
necessary operations and datatypes are natively supported by PIM hardware. For
example, our PIM implementation of decision tree is 27脳 faster than a
state-of-the-art CPU version on an 8-core Intel Xeon, and 1.34脳 faster
than a state-of-the-art GPU version on an NVIDIA A100. Our K-Means clustering
on PIM is 2.8脳 and 3.2脳 than state-of-the-art CPU and GPU
versions, respectively.
To our knowledge, our work is the first one to evaluate ML training on a
real-world PIM architecture. We conclude with key observations, takeaways, and
recommendations that can inspire users of ML workloads, programmers of PIM
architectures, and hardware designers & architects of future memory-centric
computing systems