$1\mathrm{.}5[4]$$$1\mathrm{.}6>$ Consider three different processors P$1,$ P$2,$ and P$3$ exe$-$

cuting the same instruction set. $P_1$ has a $3$ GHz clock rate and a CPI

of $1\mathrm{.}5.$ P$2$ has a $2\mathrm{.}5$ GHz clock rate and a CPI of $1\mathrm{.}0.$ P$3$ has a $4\mathrm{.}0$ GHz

clock rate and has a CPI of $2\mathrm{.}2.$