Using the full computational power of the Japanese supercomputer, K Computer, researchers from the RIKEN HPCI Program for Computational Life Sciences in Kobe, the Okinawa Institute of Technology Graduate University (OIST) in Japan and Forschungszentrum Jülich in Germany have carried out the largest general neuronal network simulation to date.

The simulation was made possible by the development of advanced novel data structures for the simulation software NEST. Even more amazing than the feat, is that NEST is open-source simulation software freely available to every scientist in the world. This allows neuroscientists to use the software to investigate neuronal systems using normal laptops, computer clusters, or even supercomputers, and easily exchange their model descriptions.

With the help of NEST, the team of scientists was able to simulate a network of 1.73 billion nerve cells connected by 10.4 trillion synapses. The program used 82,944 processors of the K Computer. The process took 40 minutes, to complete the simulation of 1 second of neuronal network activity in real, biological, time.

Even though the simulated network is huge, it still only represents 1 percent of the neuronal network in the brain. The purpose of the endeavor was to test the limits of the simulation technology developed in the project and the capabilities of the K computer. The researchers say that the experience will help guide them in building novel simulation software.

This achievement gives neuroscientists a glimpse of what will be possible in the future, with the next generation of computers, so called exa-scale computers. The simulator coordinated the use of about 1 petabyte of main memory, which corresponds to the aggregated memory of 250,000 PCs.