# What is the CPU Clock Rate? known as speed, frequency measured in Hertz (Hz)

CPU's are marching forward at the frequency of the clock.

This frequency is also known as the:

• clock speed
• clock rate
• or CPU frequency

The clock rate is the speed at which a microprocessor (CPU) executes instructions.

Every computer contains an internal clock (a clock generator) that regulates the rate at which instructions are executed by sending a signal (tick) and synchronizes all the various computer components.

## Example

A 100Mhz processor will receive 100,000,000 clock ticks every second.

## Increase

CPU clock speeds are barely increasing (Moores law hits the roof),

## Units (Mhz to ns)

• Rate often measured in:
• MHz = millions of cycles/second
• Ghz = billions of cycles/second
• Time often measured in ns (nanoseconds)

$$\begin{array}{rl} {X} \mbox{ MHz } && = && \frac{\displaystyle 1000}{\displaystyle X} \mbox{ ns} \\ 500 \text{ MHz} && \approx && 2 \text{ ns clock} \end{array}$$

## Factor

### Performance

The CPU requires a fixed number of clock ticks to execute each instruction. The faster the clock, the more instructions the CPU can execute per second.

It's the most important factor in the CPU performance (ie number of instruction by second).

### Power

Clock speed is the biggest contributor to power. Chip manufactures (Intel, esp.) pushed clock speeds very hard in the 90s and early 2000s. Doubling the clock speed increases power by 2-8x. Clock speed scaling is essentially ﬁnished. What’s Next: Parallelism. This is all the rage right now (multi-processor).

Discover More
CPU - (CPU|Processor) Time Counter

Cpu time The count of cycles, also known as clockticks, forms the basis for measuring how long a program takes to execute. See: How do you measure Execution Time? CPU Time Running which code...
CPU - (Instruction) Throughput (IPS|TIPS|GIPS|MIPS)

The throughput metrics in a CPU context is the number of instructions that can be executed in a unit of time at a given clock rate. The performance or speed of a processor depends on e.g.: the clock...
CPU - CPU Utilization

This page is the CPU Utilization metrics and is the most important metrics of all CPU metrics CPU utilization is defined as being: the amount of time spend not in the idle task. or the percentage...
CPU - Performance

The CPU performance is defined as being the number of instructions per second (IPS) that a CPU can perform known also as the CPU throughput. The performance or speed of a processor depends on e.g.: ...
Computer - Clock (generator)

Every computer contains an internal clock: the clock generator. The clock regulates the rate at which instructions are executed by sending a signal (tick) and synchronizes all the various computer components....
Computer Clock - Clock Tick (Clock Cycle)

CPU's are marching forward at some frequency, and the period of this frequency is called a Clock Tick or Clock Cycle A 100Mhz processor will receive 100,000,000 clock ticks every second. The tick...
Concurrency - Parallel Execution

Where a sequential execution can be imagined as a single worker on an assembly line moving between tasks, a parallel process is more like a series of workers, each doing a specific task. Parallelism...
Instruction - Cycle

An instruction cycle (sometimes called fetch-decode-execute cycle) is the basic operation cycle of a computer cpu. The CPU requires a fixed number of clock ticks (or clock cycles) to execute each instruction....
Instruction - Execution (Execution environment)

A execution environment is an environment that provides the facility to make instruction executable. It's a sort of context at the computer device level. Execution is the third step in a instruction...
Instruction Set - x86 (AMD, Intel)

x86 is the name of an instruction set that originated at Intel. The x86 instruction set architecture has evolved over time by: the addition of new instructions as well as the expansion to 64-bits....