Consider four processors $P1,P2,P3,$ and $P4$ executing the same instruction set. $P1$ has a $3GHz$ clock rate and a $\frac{C}{P}$I of $1\mathrm{.}5.P2$ has a $2\mathrm{.}5GHz$ clock rate and a $\frac{C}{P}$I of $1\mathrm{.}0.$

$P3$ has a $4\mathrm{.}0GHz$ clock rate and a CPI of $2\mathrm{.}0.$ P$4$ has a $8\mathrm{.}0GHz$ clock rate and a CPI of $4\mathrm{.}0.$ Which of these processor$($s$)$ has$/$have the lowest performance expressed in

MIPS?

P$1$

P$2$

P$3$

P$4$