GATE CS 2015 Set 1 Q1 — Memory Management and Virtual Memory

To find the size of the page table, we first determine the total number of pages in the logical address space.

1. Calculate the number of pages:

• Logical address size = $32\text{ bits}$
• Logical Address Space (LAS) = $2^{32}\text{ bytes}$
• Page size = $4\text{ KB} = 2^{12}\text{ bytes}$
• Number of pages = $\frac{\text{Logical Address Space}}{\text{Page Size}} = \frac{2^{32}}{2^{12}} = 2^{20}$

2. Calculate the page table size:

• Page Table Entry (PTE) size = $4\text{ bytes}$
• Page Table Size = $\text{Number of pages} \times \text{PTE size}$
• Page Table Size = $2^{20} \times 4\text{ bytes} = 4\text{ MB}$

Therefore, the size of the page table in megabytes is 4.