[en] We find that the exact hybrid algorithm in simulating QCD with four flavors of Kogut-Susskind fermions at N_t=4, with m_qa=0.025 in lattice units, is significantly more efficient than the exact Langevin algorithm, by at least a factor of 10. Comparing the integrated autocorrelation time for the plaquette τ^A and the Wilson line τ^WI on a 4⁴ lattice, we find for the exact hybrid algorithm τ^A∼10 and τ^WI∼30, while for the exact Langevin algorithm τ^A∼150 and τ^WI∼300. On a 16³x4 lattice, even if we were not able to collect enough statistics to measure the autocorrelation times reliably, the exact hybrid algorithm appears again to be more efficient by one order of magnitude