Awesome q2a theme
0 votes
14 views
A hypothetical processor on cache read miss requires one clock to send an address to Main Memory (MM) and eight clock cycles to access a 64-bit word from MM to processor cache. Miss rate of read is decreased from 14.8% to 2.6% when line size of cache is increased from one word to four words. The speed up of processor is achieved in dealing with average read miss after increasing the line size is_____
(Upto 2 decimal places)
in CO & Architecture by (64 points) | 14 views

1 Answer

0 votes
$\text{Assuming 1 cycle is required to read word from cache memory without miss}$

$\underline{\text{Under 14.8% miss rate}}$

$\text{Miss from cache to main memory to send an address }\rightarrow \text{ 1 cycle}$

$\text{Read a 64 bit word from main memory to cache } \rightarrow \text{ 8 cycles}$

$T_{avgRead } = 14.8 \times (1 + 8) + 85.2 \times 1  = 218.4 $

$\underline{\text{Under 2.6% miss rate when cache line size is increased}}$

$\text{Miss from cache to main memory to send an address }\rightarrow \text{ 1 cycle}$

$\text{Read 4 words each of 64 bit from main memory to cache } \rightarrow 4 \times 8 = \text{32 cycles}$

$T'_{avgRead } = 2.68 \times (1 + 32) + 97.4 \times 1  =  183.2$

$\text{SpeedUp} =\dfrac{T_{avgRead }}{T'_{avgRead }} = \dfrac{218.4 \text{ cycles}}{183.2 \text{ cycles}}$

$\text{SpeedUp}=1.192$
by (351 points)
Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true
Welcome to GATE CSE Doubts, where you can ask questions and receive answers from other members of the community.
Top Users Apr 2020
  1. Kushagra गुप्ता

    36 Points

  2. !KARAN

    36 Points

  3. Ram Swaroop

    36 Points

  4. sushmitagoswami

    6 Points

  5. MelinaCundif

    5 Points

  6. Lolita04I641

    5 Points

  7. JackiBandy49

    5 Points

  8. skbansal97

    5 Points

  9. lazygatestudent

    5 Points

  10. AngeloAlba89

    5 Points

3,521 questions
1,658 answers
10,461 comments
90,043 users