HORNET: A Cycle-Level Multicore Simulator

We present hornet, a parallel, highly configurable, cycle-level multicore simulator based on an ingress-queued wormhole router network-on-chip (NoC) architecture. The parallel simulation engine offers cycle-accurate as well as periodic synchronization; while preserving functional accuracy, this permits tradeoffs between perfect timing accuracy and high speed with very good accuracy. When run on six separate physical cores on a single die, speedups can exceed a factor of over 5, and when run on a two-die 12-core system with 2-way hyperthreading, speedups exceed 12×. Most hardware parameters are configurable, including memory hierarchy, interconnect geometry, bandwidth, crossbar dimensions, parameters driving power, and thermal effects. A highly parametrized table-based NoC design allows a variety of routing and virtual channel allocation algorithms out of the box, ranging from simple dimension-ordered routing to complex Valiant, ROMM, O1Turn or PROM schemes, BSOR, and adaptive routing. Hornet can run in network-only mode using synthetic traffic or traces, or directly emulate a MIPS-based multicore. Hornet is freely available under the open-source MIT license at http://csg.csail.mit.edu/hornet/.