# How do you calculate performance given clock rate and CPI?

## How do you calculate performance given clock rate and CPI?

CPU Time = I * CPI * T

- I = number of instructions in program.
- CPI = average cycles per instruction.
- T = clock cycle time.

**How is performance of a system calculated?**

The performance equation analyzes execution time as a product of three factors that are relatively independent of each other. The three factors are, in order, known as the instruction count (IC), clocks per instruction (CPI), and clock time (CT). CPI is computed as an effective value.

**What is the formula for CPI clock per instruction?**

The average CPI is the sum over each instruction of the CPI for that instruction multiplied by the fraction of the time that instruction is used. For this benchmark, Average CPI = (0.11 + 0.02)(3) + (0.52 + 0.10)(4) + (0.25)(5) = 4.12.

### How do you calculate clock rate?

The CPU multiplier (sometimes called the “CPU ratio”) is multiplied against the CPU Base Clock (or BCLK) to determine the processor’s clock speed. A CPU multiplier of 46 and a base clock of 100 MHz, for example, results in a clock speed of 4.6GHz.

**How do you calculate MIPS rate?**

- Divide the number of instructions by the execution time.
- Divide this number by 1 million to find the millions of instructions per second.
- Alternatively, divide the number of cycles per second (CPU) by the number of cycles per instruction (CPI) and then divide by 1 million to find the MIPS.

**How is performance calculated in computer architecture?**

Computer Architecture: Performance

- PERFORMANCE.
- CPU performance equation.
- T = N X S / R.
- Relative performance:
- CPU execution time for a program.
- CPU clock cycles required for a program.
- Basic components of performance.
- Components of Performance.

#### What is the basic performance formula?

R = Clock rate in cycles per second. Equ1 is referred to as the basic performance equation. To achieve high performance, the computer designer must reduce the value of T, which meansreducing N and S, and increasing R. The value of N is reduced if source program is compiled into fewer machine instructions.

**How do you calculate effective CPI?**

How to calculate effective CPI for a 3 level cache

- CPU base CPI = 2, clock rate = 2GHz.
- Primary Cache, Miss Rate/Instruction = 7%
- L-2 Cache access time = 15ns.
- L-2 Cache, Local Miss Rate/Instruction = 30%
- L-3 Cache access time = 30ns.
- L-3 Cache, Global Miss Rate/Instruction = 3%, Main memory access time = 150ns.

**What is the formula to calculate the CPI in pipelining?**

Assume also that branches are 2 cycles because of the branch delay. CPI = 0.20*1.5 + 0.20*2 + 0.6*1=1.3 cycle per instruction.

## What is clock speed?

What is clock speed? A computer’s processor clock speed determines how quickly the central processing unit (CPU) can retrieve and interpret instructions. This helps your computer complete more tasks by getting them done faster.

**How do you calculate CPI and MIPS?**

**How is CPI MIPS and execution time calculated?**

- CPU clock cycles = Instruction count x CPI.
- CPU execution time =
- = CPU clock cycles x Clock cycle.
- = Instruction count x CPI x Clock cycle.
- T =
- I.
- x CPI x C.