  This paper presents the implementation of a HLLC finite volume solver using
GPU technology for the solution of shallow water problems in two dimensions. It
compares both CPU and GPU approaches for implementing all the solver's steps.
The technology of graphics and central processors is highlighted with a
particular emphasis on the CUDA architecture of NVIDIA. The simple and
well-documented Application Programming Interface (CUDA API) facilitates the
use of the display card workstation as an additional computer unit to the
central processor. Four professional solutions of the NVIDIA Quadro line are
tested. Comparison tests between CPU and GPU are carried out on unstructured
grids of small sizes (up to 10,000 elements), medium and large sizes (up to
10,000,000 elements). For all test cases, the accuracy of results is of the
same order of magnitude for both approaches. Furthermore, the obtained speed
gains with the GPU strongly depend on the model of the graphics card, the size
of the problem and the simulation time.
