Differences Between Contiguous and Noncontiguous Memory Allocation

Comparison Chart

BASIS THE COMPARISON	CONTIGUOUS MEMORY ALLOCATION	NONCONTIGUOUS MEMORY ALLOCATION
Basic	Allocates consecutive blocks of memory to a process.	Allocates separate blocks of memory to a process.
Overheads	Contiguous memory allocation does not have the overhead of address translation while execution of a process.	Noncontiguous memory allocation has overhead of address translation while execution of a process.
Execution rate	A process executes fatser in contiguous memory allocation	A process executes quite slower comparatively in noncontiguous memory allocation.
Solution	The memory space must be divided into the fixed-sized partition and each partition is allocated to a single process only.	Divide the process into several blocks and place them in different parts of the memory according to the availability of memory space available.
Table	A table is maintained by operating system which maintains the list of available and occupied partition in the memory space	A table has to be maintained for each process that carries the base addresses of each block which has been acquired by a process in memory.

   CONTIGUOUS MEMORY ALLOCATION

  NONCONTIGUOUS MEMORY ALLOCATION

Key Differences Between Contiguous and Noncontiguous Memory Allocation

1. The basic difference between contiguous and noncontiguous memory allocation is that contiguous allocation allocates one single contiguous block of memory to the process whereas, the noncontiguous allocation divides the process into several blocks and place them in the different address space of the memory i.e. in a noncontiguous manner.
2. In contiguous memory allocation, the process is stored in contiguous memory space; so there is no overhead of address translation during execution. But in noncontiguous memory allocation, there is an overhead of address translation while the process execution, as the process blocks are spread in the memory space.
3. Process stored in contiguous memory executes faster in comparison to process stored in noncontiguous memory space.
4. The solution for contiguous memory allocation is to divide the memory space into the fixed-sized partition and allocate a partition to a single process only. On the other hands, in noncontigous memory allocation, a process is divided into several blocks and each block is placed at different places in memory according to the availability of the memory.
5. In contiguous memory allocation, operating system has to maintain a table which indicates which partition is available for the process and which is occupied by the process. In noncontiguous memory allocation, a table is maintained for each process which indicates the base address of each block of the process placed in the memory space.