Abstract This study aimed to adopt the pin-fin based passive technique to improve the heat transfer performance of the cold plate heat sink. Rectangular fins that are placed at the bottom of the channel act as an obstruction to the flow path and create chaos in the velocity field. A numerical study is carried out using Computational Fluid Dynamics (CFD) solver. A comparison is made between the parallel channel and pin fin channel for different fin length using water as a coolant. Hydraulic and thermal performance parameters like pressure drop, maximum temperature-rise, pumping power, and thermal resistance are computed and compared for several pitch values and Reynolds numbers. Pin-fin channel provides better thermal management in comparison to parallel channels that can be further improved by modulating length and width of the fin and operating at high Reynolds numbers. However, it requires more pumping power to drive the fluid through the heat sink. In the present study, a trade-off is presented among thermal resistance, pressure drop and pumping power to get an insight into optimal designs in view of a broader spectrum of the channel and pin–fin parameters.