  Topological defects unavoidably form at symmetry breaking phase transitions
in the early Universe. To probe the parameter space of theoretical models and
set tighter experimental constraints (exploiting the recent advances in
astrophysical observations), one requires more and more demanding simulations,
and therefore more hardware resources and computation time. Improving the speed
and efficiency of existing codes is essential. Here we present a General
Purpose Graphics Processing Unit implementation of the canonical
Press-Ryden-Spergel algorithm for the evolution of cosmological domain wall
networks. This is ported to the Open Computing Language standard, and as a
consequence significant speed-ups are achieved both in 2D and 3D simulations.
