Exercise 1.15

Another pitfall cited in Section 1.8 is expecting to improve the overall performance of a computer by improving only one aspect of the computer. This might be true, but not always. Consider a computer running programs with CPU times shown in the following table.

FP instr. INT instr. L/S instr. Branch instr. Total time a. 35 s 85 s 50 s 30 s 200 s b. 50 s 80 s 50 s 30 s 210 s

a) FP instr=35 s, INT instr=85 s, L/S instr=50s, Branch instr=30 s, Total time=200s

b) FP instr=50 s, INT instr=80 s, L/S instr=50s, Branch instr=30 s, Total time=210s

1.15.1 [5] <1.8> By how much is the total time reduced if the time for FP operations is reduced by 20%?

1.15.2 [5] <1.8> By how much is the time for INT operations reduced if the total time is reduced by 20%?

1.15.3 [5] <1.8> Can the total time can be reduced by 20% by reducing only the time for branch instructions?

Please show work