Question

If memory access takes 10 clock cycles, and all 7 instructions in the small computer execute an equal number of × in a benchmark, determine the CPI (Cycles Per Instruction) using the following controller:

a) 1.428
b) 2.000
c) 0.714
d) 1.000

Answer 1

The CPI (Cycles Per Instruction) is calculated by dividing the total cycles needed for all instructions by the number of instructions. Each memory access requires 10 cycles, and with 7 instructions, the total is 70 cycles. Dividing 70 by 7 gives a CPI of 10.

Step-by-step explanation:

The CPI (Cycles Per Instruction) is calculated by dividing the total cycles needed for all instructions by the number of instructions. Each memory access requires 10 cycles, and with 7 instructions, the total is 70 cycles. Dividing 70 by 7 gives a CPI of 10. When determining the Cycles Per Instruction (CPI) for a computer benchmark where each of 7 instructions takes an equal number of memory accesses and each memory access takes 10 clock cycles, we need to calculate the average number of cycles for each instruction to execute.

Since there are 7 instructions and all are executed an equal number of times, we divide the total cycles by 7 to find the CPI. As each memory access takes 10 cycles, the total number of cycles for all instructions is 7 instructions × 10 cycles per instructions, yielding 70 cycles. Therefore, the CPI is 70 cycles divided by 7 instructions, which equals 10 cycles per instruction.