In previous work, the static subpsace approximation was shown to efficiently represent the non-interacting electronic polarizability for full-frequency GW calculations for systems without partial occupations and improve computational throughput. As shown above, we extended this approach to enable full-frequency RPA total energy calculations and GW calculations with partial occupations at reduced cost. To benchmark the broadening implementations with the subspace code, we calculated the G 0 W 0 eigenvalues at high-symmetry points for bulk Cu at its experimental lattice constant and compared to the previous implementation. Table SI in the supporting information summarizes these results. Overall, we obtained overall excellent agreement with previous results given slight differences in calculation methodology. We note that the current implementation helps avoid the need for very dense (e.g. 16×16×16 or denser) k/q-grid sampling of Fermi level crossings; the results generated here used a comparatively coarse 12×12×12 k/q-grid. This k/q-grid density is consistent with previously reported RPA results for metals. The RPA correlation energy error due to the static subspace approximation depends on how well the static subspace eigenvalues/vectors, λ SS and v SS , approximate the polarizability for a nonzero frequencies. Using fewer subspace λ SS and v SS will save computational resources but could reduce accuracy. We thus quantify how the RPA correlation energy of different materials changes with fewer retained λ SS and v SS . The test materials set consisted of the same materials studied in Figure , which includes quasi-0D, quasi-2D, and 3D insulators and metals.