This study compares the thermal performances of a permanent metal mold with a conventional [pass-through cooling channel design and one with a new additively manufactured cooling channel design by investigating them both numerically and experimentally. While the conventional cooling channel metal mold was manufactured by the traditional pass-through drilled channel method, the new cooling channel metal mold was made via additive manufacturing. After the molten metal (Al6061 aluminum alloy) was poured into the mold, the temperature distribution and solidification rates of the product (valve) obtained from the metal molds were analyzed comparatively with the data taken from the inner surface of the mold in 0.5 s time steps. On the basis of temperature values on the molten side of the metal molds, it was calculated that the heat transfer rate away from the molten metal achieved by the new cooling channel design was approximately 48% higher than the conventional cooling channel. In addition, it was observed that the conventional cooling channel needed 21% more time to transfer heat away compared to the new cooling channel design.