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Difference Between Cache Memory and Virtual Memory

Computer Memory is just like a human brain used to store data and instructions either temporarily or permanently. It is a physical device capable of storing information temporarily like RAM (Random Access Memory), or permanently, like ROM (Read Only Memory). The main memory refers to physical memory, and it is known as RAM. In computer memory, we can edit or update only the data that is in the main memory. We can say that when we want to access the secondary storage media or any file that must be loaded into the main memory from the secondary device.

Cache Memory

Cache Memory is a faster memory used by the central processing unit (CPU). It is a memory that helps to reduce the access time for files or data that is recently used by the main memory. It is smaller in size, high-speed memory, and located near a processor core that stores the copies of the information or instruction frequently used by the main memory locations.

Furthermore, it behaves like a buffer between the CPU and the main memory to hold those data or programs most frequently called by the CPU. For example, whenever we execute a program by the processor, it fetches data from the main memory and fetched data to be copied to the cache memory. When the program’s copy is already available to the cache memory, it directly calls the processor to execute it; otherwise, the program/files are fetched from memory. Hence, it reduces the access time of the data from the main memory.

Advantages of Cache Memory

1. The access time of files or instruction in the cache memory is less than the main memory.
2. It stores frequently used data by the main memory.
3. It is the faster computer memory as compared to the main memory.
4. Store the program in a cache memory that is executed within a short time.

Disadvantages of Cache Memory

1. It has limited space to store the data.
2. It is very costly as it is a fast memory to access the data.

Virtual Memory

Virtual Memory is used in the computer memory to increase the storage capacity of the main memory. It is a logical storage unit of a computer that creates an illusion to execute a large program that may not be completely placed in the main memory. Furthermore, it allows the user to load or store the data program or files larger than the size of the main memory.

Advantages of Virtual Memory

1. Virtual Memory allows the users to run more than one application at once.
2. It enhances the degree of multiprogramming in the virtual memory.
3. Virtual Memory is a logical unit of computer memory that increases the main memory capacity by storing or executing a large size program than the main memory.
4. It does not require any fixed limit on the degree of multiprogramming.
5. It increases the CPU utilization in the virtual memory.
6. It is required whenever the system does not have much space to store any big programs or files.

Disadvantages of Virtual Memory

1. Virtual Memory can slow the process of application in the system.
2. It may take more time to switch between the applications.
3. It reduces the stability of the system.
4. It allows the user to lesser hard disk space for its use in the system.

Difference Between Cache Memory and Virtual Memory

S. N.	Parameter Difference	Cache Memory	Virtual Memory
1.	Definition	Cache Memory is the high speed of computer memory that reduces the access time of files or documents from the main memory.	Virtual Memory is a logical unit of computer memory that increases the capacity of main memory by storing or executing programs of larger size than the main memory in the computer system.
2.	Memory Unit	Cache Memory is defined as a memory unit in a computer system.	Virtual Memory is not defined as a memory unit.
3.	Size	Its size is very small as compared to Virtual Memory.	Its size is very large as compared to the Cache Memory.
4.	Speed	It is a high-speed memory as compared to Virtual Memory.	It is not a high-speed memory as compared to the Cache Memory.
5.	Operation	Generally, it stores frequently used data in the cache memory to reduce the access time of files.	The virtual memory keeps those data or programs that may not completely be placed in the main memory.
6.	Management	Cache Memory is controlled by the hardware of a system.	Whereas the virtual memory is control by the Operating System (OS).
7.	Mapping	It does not require a mapping structure to access the files in Cache Memory.	It requires a mapping structure to map the virtual address with a physical address.

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