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Cache memory is a small-sized type of volatile computer memory that provides high-speed data access to a processor and stores frequently used computer programs, applications and data.
A temporary storage of memory, cache makes data retrieving easier and more efficient. It is the fastest memory in a computer, and is typically integrated onto the motherboard and directly embedded in the processor or main random access memory (RAM).
Cache memory provides faster data storage and access by storing instances of programs and data routinely accessed by the processor. Thus, when a processor requests data that already has an instance in the cache memory, it does not need to go to the main memory or the hard disk to fetch the data.
Cache memory is the fastest memory available and acts as a buffer between RAM and the CPU. The processor checks whether a corresponding entry is available in the cache every time it needs to read or write a location, thus reducing the time required to access information from the main memory.
Hardware cache is also called processor cache, and is a physical component of the processor. Depending on how close it is to the processor core, can be primary or secondary cache memory, with primary cache memory directly integrated into (or closest to) the processor.
Speed depends on the proximity as well as the size of the cache itself. The more data can be stored into the cache, the quicker it operates, so chips with a smaller storage capacity tend to be slower even if it’s closer to the processor.
In addition to hardware-based cache, cache memory also can be a disk cache, where a reserved portion on a disk stores and provides access to frequently accessed data/applications from the disk. Whenever the processor accesses data for the first time, a copy is made into the cache.
When that data is accessed again, if a copy is available in the cache, that copy is accessed first so the speed and efficiency is increased. If it’s not available, then larger, more distant, and slower memories are accessed (such as the RAM or the hard disk).
Modern video cards also store their own cached memory inside their graphics processing chips. This way, their GPU can complete complex rendering operations more quickly without having to rely on the system’s RAM.
Other than hardware cache, software cache is also available as a method to store temporary files on the hard disk. This cache (also known as browser or application cache) is used to rapidly access previously stored files for the same reason: increasing speed. For example, an online browser might save some images from a web page by caching them to avoid re-downloading them every time that page is open again.