UGC-NET | UGC NET CS 2018 Dec – II | Question 24

Consider a system with 2 level cache. Access times of Level 1, Level 2 cache and main memory are 0.5 ns, 5 ns and 100 ns respectively. The hit rates of Level1 and Level2 caches are 0.7 and 0.8 respectively. What is the average access time of the system ignoring the search time within cache ?
(A) 20.75 ns
(B) 7.55 ns
(C) 24.35 ns
(D) 35.20 ns


Answer: (B)

Explanation: T(avgaccess)

= H1.T1+(1−H1)(H2.T2+(1−H2).TM) 
= (0.7∗0.5)+(0.3)((0.8∗5)+(0.2).100)
= (0.35)+(0.3)(4+20)
= 0.35+7.2
= 7.55 ns 

Option (B) is correct.

Quiz of this Question

My Personal Notes arrow_drop_up

Save