Sep 24, 2019 – 12.30 – room FORUM H

Speaker: **Yann Barsamian** (ULB)

Title: “Algorithms + Data Structures = Efficient Particle Simulations”

Short abstract: “Particle simulations are widely used in different contexts where computer simulations are needed, e.g., plasma physics, astrophysics. In this talk, we will restrict to the case where we simulate N particles on a discretized 3d grid, with the Particle-in-Cell (PIC) method: at each step of the simulation, we have O(N) computations.

Because of the required values for N and the grid size, we need to write efficient programs and use supercomputers — thousands of cores or more. In this talk, we will focus on super-computers where each node consists of multi-core processors. We will show how to reach 55% of the peak performance on these processors, measured in the roofline model. We will detail the data structure for the particles and the fields as well as the algorithm to update the particles. We will finally present a metric to compare the performance of different Particle-in-Cell implementations on different computer architectures.”