This paper is a collection of tests about the numerical computation of characteristic roots for linear delay differential equations (DDEs) with multiple discrete and distributed delays. Two different approaches are tested, based on the discretization of the infinitesimal generator of the solution operators semigroup associated to the DDE and of the solution operator itself. These approaches are implemented using different numerical techniques such as Runge-Kutta (RK), linear multistep (LMS) and spectral methods.