The increase in the heat dissipation rate in heat sinks (HSs), the reduction of the occupied volume and mass, and the elimination of the lower heat transfer areas (LHTAs) behind the pins are the main parameters to be controlled in HSs design. For this purpose, this study is devoted to numerically investigating the effect of the combination between perforation technique and splitters inserts on the heat dissipation and turbulent fluid flow characteristics of pin fins heat sinks (PFHSs). The splitter is located in the back of the pin, and the cylindrical pin fins heat sinks (CPFHSs) are perforated with different pairs of hole numbers. These configurations are named PFHS-0 (without perforation) to PFHS-5. The results obtained for the PFHS-5 show an increase in Nusselt number by 34.91% and a reduction in the thermal resistance by 24.22%, compared with CPFHSs. For the same conditions, the occupied volume and mass of this case are also reduced by 70% and 47.5%, respectively. In addition, the PFHS-5 case ensures the highest hydrothermal performance factor (HTPF) of 1.42 at Re = 8,740.