Runtime Construction of Large-Scale Spiking Neuronal Network Models on GPU Devices

Simulation speed matters for neuroscientific research: this includes not only how quickly
the simulated model time of a large-scale spiking neuronal network progresses but also how long it
takes to instantiate the network model in computer memory. On the hardware side, acceleration via
highly parallel GPUs is being increasingly utilized. On the software side, code generation approaches
ensure highly optimized code at the expense of repeated code regeneration and recompilation after
modifications to the network model. Aiming for a greater flexibility with respect to iterative model
changes, here we propose a new method for creating network connections interactively, dynamically,
and directly in GPU memory through a set of commonly used high-level connection rules. We validate
the simulation performance with both consumer and data center GPUs on two neuroscientifically
relevant models: a cortical microcircuit of about 77,000 leaky-integrate-and-fire neuron models and
300 million static synapses, and a two-population network recurrently connected using a variety of
connection rules. With our proposed ad hoc network instantiation, both network construction and
simulation times are comparable or shorter than those obtained with other state-of-the-art simulation
technologies while still meeting the flexibility demands of explorative network modeling.