I think your confused between cpu clockspeed and memory speed.
CPU clock speed:
CPU clock speed, or clock rate, is measured in Hertz — generally in gigahertz, or GHz.
A CPU's clock speed rate is a measure of how many clock cycles a CPU can perform per second.
For example, a CPU with a clock rate of 1.8 GHz can perform 1,800,000,000 clock cycles per second
Memory speed:
RAM speed is generally measured in megahertz, usually abbreviated as “Mhz.” This is a measure of the clock speed (how many times per second the RAM can access its memory)
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