Assessing the Performance of Analog Training for Transfer Learning
Omobayode Fagbohungbe, Corey Lammie, Malte J. Rasch, Takashi Ando, Tayfun Gokmen, Vijay Narayanan
TL;DR
Addressing the challenge of training neural networks on analog in-memory computing hardware for transfer learning, the paper studies the chopped TTv2 (c-TTv2) algorithm's effectiveness under realistic device non-idealities. It evaluates c-TTv2 with a Swin-ViT model pre-trained on CIFAR10 and fine-tuned on subsets of CIFAR100, employing a one-time weight-transfer noise modeled as $W_{noise}=W_{pre_trained} + τ N(0,1)$. Using IBM aihwkit to simulate HfOx ReRAM, the study explores robustness to weight-transfer noise, symmetric-point skew/variability, pulse update noise, and mean pulse DtoD variability, and compares to analog-from-scratch and digital TL baselines. The results show that c-TTv2 yields competitive or superior performance to digital TL and outperforms analog TL trained from scratch, with robustness that improves as task complexity grows; these findings support the viability of energy-efficient analog TL and guide future work toward larger models and benchmarks.
Abstract
Analog in-memory computing is a next-generation computing paradigm that promises fast, parallel, and energy-efficient deep learning training and transfer learning (TL). However, achieving this promise has remained elusive due to a lack of suitable training algorithms. Analog memory devices exhibit asymmetric and non-linear switching behavior in addition to device-to-device variation, meaning that most, if not all, of the current off-the-shelf training algorithms cannot achieve good training outcomes. Also, recently introduced algorithms have enjoyed limited attention, as they require bi-directionally switching devices of unrealistically high symmetry and precision and are highly sensitive. A new algorithm chopped TTv2 (c-TTv2), has been introduced, which leverages the chopped technique to address many of the challenges mentioned above. In this paper, we assess the performance of the c-TTv2 algorithm for analog TL using a Swin-ViT model on a subset of the CIFAR100 dataset. We also investigate the robustness of our algorithm to changes in some device specifications, including weight transfer noise, symmetry point skew, and symmetry point variability
