Using an event-driven hardware architecture to save power, TrueNorth chip runs 5.4 billion transistors at only 70 mW! TrueNorth consists of 4096 neuro-synaptic interconnected cores (as illustrated in Figure \ref{527925}c), each of which models 256 neurons with 256 synaptic inputs. Each synapse is a binary with a pre-input strength modulation shared across all neurons in the core. The architecture of TrueNorth (depicted in Figure \ref{149466}) can be thought of as an approximation of the structure of the brain within the constraints of silicon-based tech which allows it to deliver up to 400 billion synaptic operations (SOPS) per watt, whereas the most energy efficient supercomputers merely achieve 4.5 billion FLOPS per watt.