In this study, two types of heat sinks are selected at similar dimensions. In addition, five types of aluminum alloys are used to find the optimum performance for both models’ inline and cut cross heat sinks. These types of alloy materials were Al-1100, Al-3063, Al+25%Ni, and Al+25%Cu that are selected and compared with pure aluminum. The effectiveness results showed of the heat sink using Al- 25%Cu has the highest value compared to the other material types Al- 25%Ni, Al 1100, and Al 6063 respectively. While the lowest value of the fin efficiency was observed for pure aluminum. Moreover, the heat sink using Al- 25%Ni, Al 1100, and Al 6063 has moderate values. The results also indicated that the rate of heat-dissipated from the cut cross heat sink increases, as the fin thickness increases until reaches maximum value be-fore it decreases with an increase in the fin thickness. While for the inline heat sink, the heat transfer increases as the fin thickness increase before stables at 2 mm approximately.