Answer:
The answer is provided in the form of explanation
Explanation:
A page fault occurs means that the required page is not in main memory. First OS check for
page in the cache memory, if the page is present then retrieved but if not present then check for
page in main memory and if the page is not present here too then it searches for page in hard
drive. To calculate the expected time, the following formula is used:
Cache hit ratio = 95% = 0.95
Cache miss ratio = 5% = 0.05
Cache access time = 2 millisecond
The average access time of hard drive = 30 milliseconds
Expected time = Hit ratio (cache access time +memory access time) + Miss ratio (cache
access time + 2 * memory access time)
= 0.95 (2+30) + 0.05 (2+2*30)
= 0.95 (32) + 0.05(62)
=30.4 + 3.1
= 33.5 millisecond
Expected time = cache hit ratio * cache access time + (1 – hit ratio) * cache miss ratio
= 0.95*2+(1-0.95)*0.05
= 1.9025
