Supercomputing 2007: Rat-scale, near Real-time Cortical Simulations
Today, we presented a new paper at the Supercomputing 2007 conference in Reno, NV. There are estimated 9,000 attendees here!
Title: Anatomy of a Cortical Simulator
Authors: Rajagopal Ananthanarayanan and Dharmendra S. Modha
Insights into brain's high-level computational principles will lead to novel cognitive systems, computing architectures, programming paradigms, and numerous practical applications. An important step towards this end is the study of large networks of cortical spiking neurons.
We have built a cortical simulator, C2, incorporating several algorithmic enhancements to optimize the simulation scale and time, through: computationally efficient simulation of neurons in a clock-driven and synapses in an event-driven fashion; memory efficient representation of simulation state; and communication efficient message exchanges.
Using phenomenological, single-compartment models of spiking neurons and synapses with spike-timing dependent plasticity, we represented a rat-scale cortical model (55 million neurons, 442 billion synapses) in 8TB memory of a 32,768-processor BlueGene/L. With 1 millisecond resolution for neuronal dynamics and 1-20 milliseconds axonal delays, C2 can simulate 1 second of model time in 9 seconds per Hertz of average neuronal firing rate.
In summary, by combining state-of-the-art hardware with innovative algorithms and software design, we simultaneously achieved unprecedented time-to-solution on an unprecedented problem size.
Link to PDF