Difference between Fixed Partitioning and Variable Partitioning Last Updated : 12 Jul, 2025 Comments Improve Suggest changes Like Article Like Report In multi-programming, the most important methods of memory management include Fixed and Variable Partitioning. Under Fixed Partitioning memory is divided into partitions which are fixed whereas under Variable Partitioning memory partition is varied based on process size. Each has its advantages and disadvantages as to flexibility, efficiency, and the ease of using the system and is therefore appropriate for a given system.What is Fixed Partitioning?Fixed Partitioning is a contiguous memory management technique in which the main memory is divided into fixed sized partitions which can be of equal or unequal size. Whenever we have to allocate a process memory then a free partition that is big enough to hold the process is found. Then the memory is allocated to the process.If there is no free space available then the process waits in the queue to be allocated memory. It is one of the most oldest memory management technique which is easy to implement. Advantages of Fixed Partitioning Simplicity: Since partitions are already defined, it is easy to assign memory to a process especially when it is designed that way. Ease of Implementation: This makes partitioning method very easy to implement especially since it only requires partitioning of a few segments. Disadvantages of Fixed Partitioning Internal Fragmentation: If a process is not able to fill a partition it uses then there is space left in that partition which is not utilized. Inefficient Memory Utilization: The size of partitions is fixed and therefore large processes might occupy more space while small processes occupy inadequate large space. Limited Process Size: Quantities greater than the size of the largest partition cannot be performed; this decreases flexibility.What is Variable Partitioning?Variable Partitioning is a contiguous memory management technique in which the main memory is not divided into partitions and the process is allocated a chunk of free memory that is big enough for it to fit. The space which is left is considered as the free space which can be further used by other processes. It also provides the concept of compaction. In compaction the spaces that are free and the spaces which not allocated to the process are combined and single large memory space is made. Advantages of Variable PartitioningEfficient Memory Utilization: Memory is allocated dynamically; this means that it can be used sparingly thus avoiding the use of much space on the available memory.No Process Size Limitation: One advantage of this is an absence of sharp partitions because memory is allocated as per the processes requirements.Higher Degree of Multi-programming: It also stated that process flexibility for memory can be suitable for more process.Disadvantages of Variable PartitioningExternal Fragmentation: Any time memory space is granted and then recalled for someone else to free, space of maximum un-utilized portions of memory are created termed as external fragmentation leading to poor memory utilization.Complexity: Fixed partitioning and its related concepts are far simpler to handle and control as compared to variable partitions and external fragmentation.Need for Compaction: To avoid this fragmentation, compaction is needed, in which the free areas are grouped together to form bigger spaces in the memory, but this takes a lot of time and consumes many resources.Difference between Fixed Partitioning and Variable Partitioning Fixed PartitioningVariable PartitioningMemory is divided into fixed-sized partitions. Memory is allocated dynamically in varying sizes.Only one process can be placed in each partition.A process is allocated a chunk of free memory as needed.Inefficient memory utilization due to internal fragmentation.More efficient memory utilization with less internal fragmentation.Internal and external fragmentation occur.Only external fragmentation occurs.Limited degree of multi-programming.Higher degree of multi-programming due to flexible allocation.Easier to implement.More complex to implement.Restricts process size based on partition size. No size limitation on processes.ConclusionSo, Fixed Partitioning and Variable Partitioning both are high memory management strategies used under multi-programming. However, comparing to Fixed Partitioning, it is simpler and easier to implement and it can cause inefficiency and has less flexibility at the same time. However, Variable Partitioning uses even less memory and can manage larger processes; on the flip side, the procedure is more monumental and may lead to external fragmentation. The decision whether to use one technique or the other depends with the requirement of the system in terms of simplicity, memory required, and flexibility required in the processes. Comment More infoAdvertise with us Next Article What is an Operating System? K kapilsparshi Follow Improve Article Tags : Operating Systems Difference Between GATE CS Similar Reads Operating System Tutorial An Operating System(OS) is a software that manages and handles hardware and software resources of a computing device. 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Different 13 min read PracticeLast Minute Notes – Operating SystemsAn Operating System (OS) is a system software that manages computer hardware, software resources, and provides common services for computer programs. It acts as an interface between the user and the computer hardware.Table of Content Types of Operating System (OS): ThreadsProcessCPU Scheduling Algor 15+ min read Operating System Interview QuestionsAn operating system acts as a GUI between the user and the computer system. In other words, an OS acts as an intermediary between the user and the computer hardware, managing resources such as memory, processing power, and input/output operations. Here some examples of popular operating systems incl 15+ min read Operating Systems - GATE CSE Previous Year QuestionsThe Operating System(OS) subject has high importance in GATE CSE exam because:large number of questions nearly 10-12% of the total asked significant weightage (9-11 marks) across multiple years which can also be seen in the below given table:YearApprox. Marks from OSNumber of QuestionsDifficulty Lev 2 min read Like