Differences between cache and main memory (RAM)

The main difference between cache and Random Access Memory (RAM) is cache has a smaller storage capacity and is faster than the main memory. While RAM stores data that is currently being executed cache stores the most frequently used instructions. The cache is within the CPU chip, unlike RAM which is a separate component on the motherboard.

Both RAM and cache are volatile memory which means they keep data only when the device is powered. They also store data temporarily unlike secondary storage like hard disks and optical disks. The 2 memories are among the factors that determine the speed and performance of any computer system.

What is the Main memory of a computer?

RAM is also called the primary memory of the computer. This is because it is the core memory that stores any data before it can be executed on the processor. A computer cannot operate without a main memory. You can read more on the types, functions, and storage capacity of main memory in this other article.

What is cache memory?

It is a fast-access type of memory that is close to the CPU to increase its operating speed. Cache memory was invented to speed up the processor since RAM was slow which reduced computer speed. The larger the cache memory the faster the computer can retrieve required data hence its speed. To expand more cache memory we have another article here on levels, functions, characteristics, and advantages of cache memory for you.

Differences between cache and RAM memory

Criteria for comparison	Cache Memory	Main Memory (RAM)
Definition	Also known as CPU memory is a fast memory that helps to increase the performance of a computer processor	Also known as primary or main memory is the core memory where data that is being currently executed is stored.
Purpose	Holds most frequently used data	It holds data that is currently being processed
Memory capacity	The cache size range from Kilobytes to Megabytes. Level 3 cache for most computers has 32MB	RAM memory capacity is in Gigabytes. I standard computer can have 4GB or 8GB which can be upgraded to an even high capacity.
Access Speed	They operate at the speed of the processor. This is specifically for Level 1 and 2 caches.	Compared to cache memory they are slow.
Cost	They are more expensive to manufacture. This is why they are limited storage capacity	They are cheaper than the cache memory
Technology used	Most caches use Static RAM technology to manufacture	Most main memories are Dynamic RAM which is cheaper and simpler to manufacture.
Where is it located	Cache memories are integrated within the CPU microchip.	RAMs are within the computer motherboard on the memory slot
Duration of data storage	Cache memories are volatile which means when the power goes OFF they lose data.	They are volatile. RAM just cache they store data only when the computer has power.
Examples and types	Level 1, level 2, and level 3	Dynamic RAM and Static RAM