A CPU with a heat sink (e.g. Intel Pentium 4 and Intel Pentium dual core) is one of the challenging problems for IEEE EMC. A Very Large Scale Integrated (VLSI) device was modelled using the Finite Element Method (FEM) frequency domain as this provides a 3D full wave solution. The electromagnetic (EM) radiation emitted from these high power microelectronic circuits connected to a heat sink was found to have resonant frequencies around 2.4 GHz and 5 GHz with a reflection coefficient less than 19 dBi and 8 dBi. Those resonant frequencies are very close to the operating frequency of both IEEE and Bluetooth wireless communication systems. This paper proposes a new benchmark model based on a dual core CPU.