7/25/2019 computer architecture solution

1/3

Homework #1

CAD

1. [5pts] Find the CPI (Cycle Per Instruction) if the clock cycle time is 0.333 nnoseconds.

!ns" 0.#$

%ethod"

CPI = execution time / (instruction count * clock cycle time)

&

750

(2.3891012 )(0.333109)

=750

796

& 0.#$

'. [5pts] Find the PCrtio.

!ns" 1'.#

%ethod"

As per definition SPECratio defined as,

SPECratio = reference time / execution time

&9650

750

& 1'.#

3. [5pts] find the increse in CP* time if the num+er of instructions of the +enchmrk is

incresed +y 10, -ithout ffectin the CPI.

!ns"

Increase in CP time = ! " #$%/&' = ! (!)

instruction count * !! = $+$#, CP time = #$%s

$. [5pts] find the increse in the CP* time if the num+er of instructions of the +enchmrk

is incresed +y 10, nd the CPI is incresed +y 5,.

7/25/2019 computer architecture solution

2/3

!ns"

increase in CP time = !/&' " ! = $ ($)

CPI * !! = !%, CP time = !s

5. [5pts] find the chne in the PCrtio for this chne

!ns"

SPECratio for t-is c-an.e = !&

/. [10pts] uppose tht -e re deelopin CP* -ith $ 24 clock rte. e he lso

dded some dditionl instructions to the instruction set so tht the num+er of instructions

hs +een incresed +y 15,. 6he e7ecution time is reduced to 800 seconds. Find the ne-

CPI.

!ns"

CPI ne = !%#instruction count ne = $%!E!$, clock rate = 0 x !

8. [10pts] 6his CPI lue is lrer thn o+tined in the 9uestion 1 +oe s the clock rte

-s incresed from 3 24 to $ 24. :etermine -hether the increse in the CPI is similr

to tht of the clock rte. If they re dissimilr; -hy