In Fig. , the benchmark result of the computational performance of the double-precision DMRG method and the mixed-precision DMRG scheme is presented, as well as the corresponding speed-up between these two approach. The testing systems are the same to those in Table . The performance of the mixed-precision scheme is, as expected, better than the double-precision method. Even a 2.31 speed-up is achieved for the benzene system with the active space of (24e,24o) and a bond dimension of 5000. This speed-up is larger than the theoretical upper bond of the speed-up for mixed-precision optimization. This is because the total number of sweeps is decreased for the mixed-precision scheme. Generally, the number of sweeps for the mixed-precision scheme is slightly different from the double-precision method, but will not be far from it.