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Hardware Support for Page Table using TLB

A paging sche...

Question

A paging scheme uses a Translation Look-aside Buffer (TLB). A TLB-access takes 10 ns and a main memory access takes 50 ns. What is the effective access time (in ns) if the TLB hit ratio is 90% and there is no page-fault?

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Solution

Effective access time = hit ratio * (TLB access time + Memory access time) + miss ratio * (TLB access time + Page table access time + Memory access time )

=0.9 * (10 + 50) + 0.1 (10 + 50 + 50 )
= 54 + 11 = 65

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