Section Three: Calculating the following questions.$(10$ points $*2$

$1)$ Have a brief introduction of Amdahl's Law

$2)$ Assume the frequency of the FP$($ Float Point $)$ instructions is $25\%,$ and its average CPI is $5\mathrm{.}0,$ and the frequency of non$-$FP instructions is $2\mathrm{.}33.$ FPSQR$($ Float Point square$)$ instructions come up to $5\%,$ and its average CPI is $20,$

we have two kinds of Optimization Method to optimize this situation below,

$1.$ Decrease the CPI of FPSQR to $2$

$2.$Decrease the CPI of FP to $2\mathrm{.}5$

try to calculate the Average CPI of these two different methods respectively, the results are supposed to keep two significant digits.

$3)$ Here we have $100$ processor $.$ In order to get the speed$-$up ratio at $50,$ try to calculate the degree of parallelism of this community $,$ the results are supposed to keep four significant digits.