What Is Page Fault Time

A page fault occurs when the referenced page is not found in the main memory. … The time taken to service the page fault is called as page fault service time.

How long does a page fault take?

It takes 8 milliseconds to service a page fault if an empty page is available or the replaced page is not modified, and 20 milliseconds if the replaces page is modified. Memory access time is 100 nanoseconds.

How is page fault service time calculated?

Here memory access time (m) = 4μsec, page fault service time = 20ms and hit ratio = 99.9% so, miss ratio or page fault ratio = (1 – 99.99%) = 0.01%, so page fault rate 0.01/100 = 0.0001 i.e. 10 4 . So, Effective Memory Access Time (EMAT) for this above example is 6μsec.