Order 104 speedup in global linear instability analysis using matrix formation

► Spatial discretization for Local, BiGlobal and TriGlobal linear stability analysis. ► FD-q stable high-order finite-difference scheme applied for the first time. ► Spectral Collocation (SC), Summation-by-parts, Padé, DRP and FD-q methods compared. ► FD-q scheme outperforms both the SC method and all its FD peers. ► Speedup of O(104) and memory reduction O(103) was documented.