Problem 3 (15 points): Assume that we are considering enhancing a machine by adding a vector mode to it. When a computation is performed in vector mode, it is 20 times faster than the normal mode of execution. We call percentage of time that could be spent using vector mode the percentage of vectorization. a. b. What percentage of vectorization is needed to achieve a speedup of 2? What percentage of vectorization is needed to achieve one-half of the maximum speedup attainable from using vector mode? c. Suppose you have measured the percentage of vectorization for programs to be 70%. The hardware design group says they can double the speed of vector rate with a significant additional engineering investment. You wonder whether the compiler crew could increase the use of vector mode as another approach to increasing performance. How much of an increase in the percentage of vectorization (relative to the current usage) would the compiler team need to obtain the same performance gain? Which investment would you recommend? Problem 4 (15 points): Assume a program requires the execution of 50 x 106 FP (Floating Point) instructions, 110 x 106 INT (integer) instructions, 80 x 106 L/S (Load/Store) instructions, and 16 x 106 branch instructions. The CPI for each type of instruction is 1, 1, 4, and 2, respectively. Assume that the processor has a 2GHz clock rate. a. By how much must we improve the CPI of FP (Floating Point) instructions if we want the program to run two times faster? b. By how much must we improve the CPI of L/S (Load/Store) instructions if we want the program to run two times faster? c. By how much is the execution time of the program improved if the CPI of INT (Integer) and FP (Floating Point) instructions are reduced by 40% and the CPI of L/S (Load/Store) and Branch is reduced by 30%? Problem 5 (10 points): Processor A has a clock rate of 3.6 GHz and voltage 1.25V. Assume that, on average, it consumes 90W of dynamic power. Processor B has a clock rate of 3.4 GHz and voltage of 0.9V. Assume that, on average, it consumes 40W of dynamic power. For each processor find the average capacitive loads. Problem 3 (15 points): Assume that we are considering enhancing a machine by adding a vector mode to it. When a computation is performed in vector mode, it is 20 times faster than the normal mode of execution. We call percentage of time that could be spent using vector mode the percentage of vectorization. a. b. What percentage of vectorization is needed to achieve a speedup of 2? What percentage of vectorization is needed to achieve one-half of the maximum speedup attainable from using vector mode? c. Suppose you have measured the percentage of vectorization for programs to be 70%. The hardware design group says they can double the speed of vector rate with a significant additional engineering investment. You wonder whether the compiler crew could increase the use of vector mode as another approach to increasing performance. How much of an increase in the percentage of vectorization (relative to the current usage) would the compiler team need to obtain the same performance gain? Which investment would you recommend? Problem 4 (15 points): Assume a program requires the execution of 50 x 106 FP (Floating Point) instructions, 110 x 106 INT (integer) instructions, 80 x 106 L/S (Load/Store) instructions, and 16 x 106 branch instructions. The CPI for each type of instruction is 1, 1, 4, and 2, respectively. Assume that the processor has a 2GHz clock rate. a. By how much must we improve the CPI of FP (Floating Point) instructions if we want the program to run two times faster? b. By how much must we improve the CPI of L/S (Load/Store) instructions if we want the program to run two times faster? c. By how much is the execution time of the program improved if the CPI of INT (Integer) and FP (Floating Point) instructions are reduced by 40% and the CPI of L/S (Load/Store) and Branch is reduced by 30%? Problem 5 (10 points): Processor A has a clock rate of 3.6 GHz and voltage 1.25V. Assume that, on average, it consumes 90W of dynamic power. Processor B has a clock rate of 3.4 GHz and voltage of 0.9V. Assume that, on average, it consumes 40W of dynamic power. For each processor find the average capacitive loads
