Hermes is a speculative mechanism that accelerates long-latency off-chip load requests by removing on-chip cache access latency from their critical path. The key idea behind Hermes is to: (1) accurately predict which load requests might go to off-chip, and (2) speculatively start fetching the data required by the predicted off-chip loads directly from the main memory in parallel to the cache accesses. Hermes proposes a lightweight, perceptron-based off-chip predictor that identifies off-chip load requests using multiple disparate program features. The predictor is implemented using only tables and simple arithmetic operations like increment and decrement.