GATE Question on TLB

GATE | GATE-CS-2014-(Set-3)

Consider a paging hardware with a TLB. Assume that the entire page table and all the pages are in the physical memory. It takes 10 milliseconds to search the TLB and 80 milliseconds to access the physical memory. If the TLB hit ratio is 0.6, the effective memory access time (in milliseconds) is _________.

A. 120
B. 122
C. 124
D. 118

Given,

Effective Access Time (EAT) = 0.6 ( 10 + 80 ) + 0.4 ( 10 + 80 + 80 ) = 90 X 0.6 + 0.4 X 170 = 122

Hence, the right answer is option B.