Last Updated :
22 Nov, 2018
What is the average access time for a system which supports 2 level of hierarchical memory organization and has the following specification:
(A) 120 ns
(B) 124 ns
(C) 126 ns
(D) 130 ns
Answer: (D)
Explanation: L1 access time T1 = 10 ns
L2 access time = 50
L2 access time T2 = 50*6 (given block is 6 word) = 300 ns.
Now, hit ratio of L1
= 100% - 40%
= 60%
= 0.6
And, miss ratio for highest level is always 0. Hit ratio of L2
= 100% - 0%
= 100%
= 1
Therefore, TAvg
= H1T1 + (1 -H1) * H2 *(T1 + T2)
= 0.6 * 10 + 0.4 * 1 * (10 + 300)
= 6 + 124
= 130 ns
So, option (D) is correct.
Quiz of this Question
Share your thoughts in the comments
Please Login to comment...