Question

In a computer system, memory mapped. access takes 100 nanoseconds when a page is found in tlb. in case the page is not tlb, it takes 400 nanoseconds to access. assuming a hit ratio of boyi, the effective access time is :

(1) 120 nanoseconds
(2) 160 nanoseconds
(3) 200 nanoseconds
(4) 500 nanoseconds

Answer 1

Option 1. The effective access time in a computer system can be calculated by considering the hit ratio of the TLB and the access time of the TLB and the main memory.

Step-by-step explanation:

The effective access time in a computer system can be calculated by taking into consideration the hit ratio of the TLB (Translation Lookaside Buffer) and the access time of the TLB and the main memory. Let's assume that the TLB hit ratio is 'h', which means '1-h' is the probability of a TLB miss.

In this case, when a page is found in the TLB, the access time is 100 nanoseconds, and when a page is not found in the TLB, it takes 400 nanoseconds to access. Therefore, the effective access time can be calculated as:

Effective Access Time = (h * 100) + ((1-h) * 400)

For the given options, the effective access time will be 120 nanoseconds when the hit ratio is 0.4 or 40%. Therefore, the correct answer is option (1) 120 nanoseconds.