Connectionists: New Paper: "Anatomy of a Cortical Simulator" at Supercomputing 2007

[Dharmendra Modha]

TITLE:  Anatomy of a Cortical Simulator

 

AUTHORS:  Rajagopal Ananthanarayanan and Dharmendra S. Modha, IBM Almaden
Research Center

 

CONFERENCE: Supercomputing 2007, Reno, NV, Nov 10-16

 

ABSTRACT:  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 FILE:
http://sc07.supercomp.org/schedule/event_detail.php?evid=11063