GATE CS 2014 Set 1 Q55 — Instruction Pipelining

The execution time $T$ of a program on a processor is given by the formula:

where $I$ is the instruction count, $\text{CPI}$ is the clock cycles per instruction, and $f$ is the clock frequency.

Let the parameters for processor $P_1$ be $T_1$, $\text{CPI}_1$, and $f_1 = 1\text{ GHz}$. Since both processors execute the same program, the instruction count $I$ remains the same.

For processor $P_2$, we are given:

• Execution time: $T_2 = 0.75 \times T_1$
• CPI: $\text{CPI}_2 = 1.20 \times \text{CPI}_1$

Using the execution time formula for both processors:

Substituting $f_1 = 1\text{ GHz}$:

Thus, the clock frequency of $P_2$ is 1.6 GHz.