In the computer CPU power circuit, electrolytic capacitors are used as decoupling capacitors of power. When the CPU load varies at a high speed condition, three types of capacitors were investigated to provide instantaneous current for stabilization of power voltage. The results show that PA-Cap multilayer polymer aluminum electrolytic capacitors has the extremely small Res value and the very high conductivity. The Res (23 mΩ) and △V (–90 mV) of 56 μF polymer capacitor are better than 220 μF Ta capacitor and Al electrolytic capacitor. Therefore, PA-Cap polymer capacitors to use in the switching power supply and the digital circuit is the best choice.