The calculation accuracy of the newly developed 3D discrete ordinates code, Attila, is benchmarked by comparing its prediction to the measured data in two mockups bombarded by 14 MeV neutron source of the FNG facility located at Frascati, Italy. The results are also compared to those based on MCNP Monte Carlo code for the same measured reactions. The experimental mock-ups simulate parts of ITER in-vessel components, namely, the tungsten (W) mockup and the ITER shielding blanket. The first mockup was used to validate W data as a material for plasma facing component. A streaming path was introduced in the second configuration. The objective of this paper is to benchmark Attila code to determine its adequacy for fusion application. Another objective is to compare results based on two distinctive 3D calculation tools using the same nuclear data, FENDL2.1, and the same response function (IRDF-90) for measured data. The results of these comparisons are reported in this paper.