Question

Assume a program requires the execution of 50 x 106 FP instructions, 110 x 106 INT instructions, 80 x 106 L/S instructions, and 16 x 106 branch instructions. The CPI for each type of instruction is 1 1, 4, and 2, respectively. Assume that the processor has a 2 GHz clock rate 1.141 [10] <$1.10 By how much must we improve the CPI of FP instructions if we want the program to run two times faster? 1.14.2 [10]

Answer 1

Step-by-step explanation:

FP -
`50 * 10^6`

CPI - 1

INT -
`110 * 10^6`,

CPI - 1

I/S -
`80 * 10^6` ,

CPI - 4

Branch -
`16 * 10^6`

CPI - 2

Clock Speed -
`2 * 10^9`

Time(old) =
`(50 x 10^6 + 110 x 10^6 + 4 x ( 80 x 10^6) + 2 x (16 x 10^ 6))/(2 x 10^9)`

Time(old) =
`256 * 10^ {-3}`

Time(new) =
`(256 * 10^(-3))/(2)`

=
`128 * 10^(-3)`

=
`(CPI(new) x [50 x 10^6 + 110 x 10^6 + 4 x ( 80 x 10^6) + 2 x (16 x 10^ 6)])/(2 x 10^9)`

=
`128 * 10^(-3)`

CPI(new) =
`(-206)/(50)`

= -4.12