Difference between Cache and RAM

Before discussing the above categories, let's define computer memory. The data is kept as 0s and 1s so the user can save and retrieve it. Memory is like a person's brain. Computer memory allows speedy data access. The CPU may talk to the application faster. Without computer memory, the user couldn't save anything.

Computer memory stores data either temporarily or permanently, based on which it is classified as either primary (internal memory) or secondary (external memory).

There are two types of memory −

  • External Memory − Most of the time, external memory means storing files on an external hard drive or on the Internet. The computer's work area is its main memory, not its storage space.

  • Internal Memory − The computer's main memory is called its internal memory or internal storage. You can quickly get data in primary memory, which is either volatile, like RAM, or nonvolatile, like ROM.

The amount of data that can be stored in primary memory is also limited and usually less than that of secondary memory. In main memory, the data and programs that need to be run directly by the CPU are kept in the Internal memory. The CPU and the primary memory talk to each other directly. It is in the middle of the memory hierarchy because it talks directly to the CPU and indirectly with the secondary memory through the I/O Processor.

It is often called semiconductor memory because it is made with semiconductor technology. There are two kinds of primary memory −

  • RAM

  • ROM

What is RAM?

Random Access Memory, or RAM, is a type of computer memory that stores data while the computer is running so that the processor can get to it quickly. All the data on this memory will be lost if the power supply fails, is cut off, or stops. RAM is used to start the computer or boot up. It temporarily stores programmes and data that the processor needs to be able to run.

RAM is where the operating system, application programs, and data that are being used right now are kept. Reading from RAM is much faster than reading from the hard drive. RAM is kept on microchips, and it has a lot less information than the hard disk. RAM can never run out of space, but if it does, the processor has to overwrite old data, which slows down the computer. Any file in RAM can be directly accessed if the user knows the row and column numbers.

Random access memory is used to store temporary but important information on a computer so that programs or applications can quickly get to it.

Types of RAM

RAM can be either static or dynamic.

  • Static RAM (SRAM) − It uses transistors, and as long as the power is on, the memory can hold its state as long as the power is on. This memory is made up of a number of flip-flops, and each flip-flop holds one bit. It is faster because it takes less time to get to. Static RAM is most often used for programs that don't need a lot of RAM memory. You could think of SRAM as being used to make all of the main memory, but that would be too expensive.

  • Dynamic RAM (DRAM) − DRAM is also another type of RAM that stores each bit of data in a separate capacitor inside an integrated circuit. This means that each memory cell in a DRAM chip is made up of a transistor and a capacitor and holds one bit of data. Where the memory controller needs to read the data and then rewrite it, constantly refreshing. Because of this process, DRAM is slower than SRAM. But DRAM is less expensive than SRAM, so it is used as the main memory in a CPU. Even though it is slower than SRAM, it is still pretty fast and can connect directly to the CPU bus.

What is Cache Memory?

Cache Memory is a type of memory that is very fast and unique. It is used to speed up and get in sync with a fast CPU. Cache memory costs more than main memory, disk memory, and CPU registers, but less than main memory or disc memory.

Cache memory is a type of memory that acts as a buffer between the processor and the main memory. It works very quickly. It stores frequently used data and instructions so that the CPU can use them right away when it needs to. Cache memory speeds up access to Main memory. The cache retains copies of frequently used material from main memory. Many independent CPU caches store data and instructions.

The CPU checks the cache before reading or writing to main memory. If the CPU finds the memory location in the cache, it reads the data. A "cache miss" occurs when the CPU can't find the cached memory. The cache creates a new entry and copies data from main memory when a request is missed. Cache fills the request.

Difference between RAM and Cache Memory

The cache is faster, cheaper, and smaller than RAM. The cache memory caches CPU data and programs often and quickly. RAM contains the CPU's current data and applications. The cache caches CPU-needed data and programs. RAM contains currently-used data and programs.

The following table highlights the major differences between RAM and Cache memory −

Basis of Comparison
Cache Memory
The term "main memory" refers to the same thing as "random access memory." It is a memory unit that communicates in a straightforward manner with the central processor unit (CPU).
Cache memory is used to store data that is used often so that it can be quickly accessed when needed.
The size of RAM is bigger than that of cache memory.
Cache memory is less in size.
RAM is expensive.
Cache memory is not much expensive.
It is not faster than Cache memory.
It is faster than RAM.
It is used to hold the programs and related data that are currently executed by the CPU.
It is used to store the data which are frequently used by the CPU.


Compared to RAM, Cache is faster, smaller, and costs more money. The cache is very helpful because it makes the main memory faster, lets you get to data quickly, and speeds up output.

Updated on: 06-Jul-2022

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