Clock gating is one of the power-saving techniques used on the Pentium 4 processor. To save power, clock gating refers to activating the clocks in a logic block only when there is work to be done. From the earliest days of the Pentium 4 processor design, power consumption was a concern. The clock gating concept isn’t a new one; however, the Pentium 4 processor used this technology to a large extent. Every unit on the chip has a power reduction plan, and almost every Functional Unit Block (FUB) contains clock gating logic.