Reliable Hyperdimensional Reasoning on Unreliable Emerging Technologies

While Graph Neural Networks (GNNs) have demonstrated remarkable achievements in knowledge graph reasoning, their computational efficiency on conventional computing platforms is impeded by the memory wall problem. To overcome these challenges, we introduce an innovative algorithm-hardware solution that harnesses the potential of hyperdimensional computing (HDC) for robust and memory-centric computation on computing in-memory (CiM) platforms. Departing from traditional graph neural networks, the proposed HDC reasoning model employs a symbolic approach to effectively encode graph entities and their relationships as high-dimensional neural activity. Complementing this approach is a customized Computing-in-Memory (CiM) architecture based on advanced Ferroelectric Field-Effect Transistor (FeFET) technology, which incorporates a precise characterization of non-idealities. This modeling enables the generation of an HDC-tailored model that faithfully represents the hardware architecture. Despite the non-idealities inherent in emerging CiM technologies, our platform demonstrates performance on par with traditional von Neumann architectures for substantial combinations of FeFET device parameters. Our solution overcomes FeFET CiM the increased non-idealities from down-scaled 3nm, operating effectively under all possible configurations when 50 graph edges are considered. Scenarios with less than 4-bit precision per FeFET device cannot handle graphs with more than 200 edges, whereas the 4-bit case can achieve a 90.3% graph reconstruction rate on the worst-case scenario of 80% of noise.