To find the average CPI, more data is needed. The execution time of a program on a 2.5GHz processor, assuming 3 cycles per instruction and 100 million instructions, is 0.12 seconds. Evaluating performance with a memory access change at 4 GHz requires more specific program data.
Finding the Average CPI and Execution Time on a Processor
To calculate the average CPI (Cycles Per Instruction) for a program on a Pentium chip, we would need more specific data on the number of instructions and the cycle count for those instructions. However, if we were given that a Pentium chip executes more than 100 million instructions per second, and knowing the frequency of the processor, we can estimate the time it takes to execute the program.
For a 2.5GHz processor, which is 2.5 billion cycles per second, we would divide the total cycle count by this frequency to find the execution time:
Execution Time = Total Cycles / Frequency
If the program takes 3 cycles per instruction and assuming we have 100 million instructions, then:
Total Cycles = Number of Instructions × CPI
Execution Time = (100,000,000 × 3) / 2,500,000,000 = 0.12 seconds
When considering the memory access modification (2 clock cycles per access at 4 GHz frequency), the performance depends on the number of memory accesses and the ratio between computation and memory access time. In some cases, such modification could lead to improved performance; in others, it might not.
To provide a more definitive answer on performance improvement, the number of memory accesses and the instruction mix of the program would need to be analyzed. With the given information, it is not possible to conclude if the performance would be better or worse without more data on how memory access influences overall execution time.