Exercise 1.14

Section 1.8 cites as a pitfall the utilization of a subset of the performance equation as a performance metric. To illus trate this, consider the following data for the execution of given instruction sequence of 106 instructions in different processors.

Processor Clock rate CPI P1 4 GHz 1.25 P2 3 GHz 0.75

p1) clock rate=4 GHz, CPI=1.25

p2) clock rate=3 GHz, CPI=0.75

1.14.1 [5] <1.8> One usual fallacy is to consider the computer with the largest clock rate as having the large performance. Check if this is true for P1 and P2.

1.14.2 [10] <1.8> Another fallacy is to consider that the processor executing the largest number of instruction will need a larger CPU time. Considering that processor P1 is executing a sequence of 106 instructions and that the CPI of processors P1 and P2 do not change, determine the number of instructions that P2 can execute in the same time that P1 needs to execute 106 instructions.