The term "quad-core processor" refers to a central processing unit (CPU) that integrates four separate processors on a single chip in order to perform four separate tasks simultaneously. The numbers 1.8 and 2.2 refer to speed ratings in terms of gigahertz, or billions of cycles per second.\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t \t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tSpeed
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CPU manufacturers judge speed by "clock rate." According to The PC Guide, this is the number of times per second the processor works to execute software instructions. A 2.2 GHz CPU works on software instructions 0.4 billion more times per second than a 1.8 GHz processor.
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HP states that the faster a CPU works, the more energy it consumes. Assuming a 2.2 GHz and a 1.8 GHz processor with the same energy efficiency are made to perform the same tasks, the 2.2 GHz unit will consume more power. In a laptop computer, this would result in shorter battery life.
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All things being equal, a 2.2 GHz processor generates more heat than a 1.8 GHz processor. This could necessitate a larger fan and cooling system, resulting in a larger and louder computer.
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