A computer motherboard includes a motherboard substrate defining a CPU loading area and a CPU voltage regulator power supply layout area. The power supply layout area is equally divided into a number of phase regions, and each of the phase regions has a number of spaced circuit layers. The circuit layers in the phase regions are symmetrical about a central axis of the CPU loading area, and a difference between each two simulating impedances between an impedance center of each of the phase regions and a loading center of the CPU loading area is within 1%.