The Hodgkin–Huxley model assumes independent ion channel activation, although mutual interactions are common in biological systems. This raises the problem why neurons would favor independent over cooperative channel activation. In this study, we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy consumption. Simulations of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that, while cooperative activation enhances neuronal information processing capacity, it greatly increases the neuron’s energy consumption. As a result, cooperative activation of sodium channel degrades the energy efficiency for neuronal information processing. This discovery improves our understanding of the design principles for neural systems, and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases.