retagged by
3,788 views
0 votes
0 votes

Suppose TLB used in one level paging system with each look-up time of TLB 40 msec. Memory reference takes 120 msec. If the effective memory reference time is 180 msec then page table references are found in TLB is ______

Answer Given in booklet (0.833)

retagged by

2 Answers

Best answer
4 votes
4 votes
I think they are asking of TLB hit ratio:

Effective access time = 180msec

TLB access time = 40msec

Main memory access time = 120msec

Therefore, 180 = x(40 + 120) + (1-x)(40 + 2*120)

x = 0.8333
selected by
0 votes
0 votes
we have to find the TLB Hit Ratio.

Given EMAT = 120, TLB lookup =  40, Memory = 160 everything in millisec.

Now,

EMAT = t + m  + pm  here p is (miss ratio)

180 = 40 + 120 +p(120)

120p = 20

so, p = 0.166 (.ie miss ratio) to find hit ratio use hit ratio = 1-p = 1 - 0.16 = 0.844

Related questions

2 votes
2 votes
3 answers
1
Veerendra V asked Nov 8, 2016
6,804 views
Consider a paging system uses, TLB’s access time is 30 ns and memory access time is 200ns. If the effective memory access time is 150ns, what will be the hit ratio of T...