We are rapidly approaching an inflection point where the conventional target of producing perfect, identical transistors that operate without upset can no longer be maintained while continuing to reduce the energy per operation. With power requirements already limiting chip performance, continuing to demand perfect, upset-free transistors would mean the end of scaling benefits. The big challenges in device variability and reliability are driven by uncommon tails in distributions, infrequent upsets, one-size-fits-all technology requirements, and a lack of information about the context of each operation. Solutions co-designed across traditional layer boundaries in our system stack can change the game, allowing architecture and software (a) to compensate for uncommon variation, environments, and events, (b) to pass down invariants and requirements for the computation, and (c) to monitor the health of collections of devices. Cross-layer codesign provides a path to continue extracting benefits from further scaled technologies despite the fact that they may be less predictable and more variable. While some limited multi-layer mitigation strategies do exist, to move forward redefining traditional layer abstractions and developing a framework that facilitates cross-layer collaboration is necessary.
['André DeHon', 'Heather Quinn', 'Nicholas P. Carter']
Vision for cross-layer optimization to address the dual challenges of energy and reliability