When cache memory comes into existence?
Data in primary memory can be accessed faster than secondary memory but still, access times of primary memory are generally in a few microseconds, whereas the CPU is capable of performing operations in nanoseconds. Due to the time lag between accessing data and acting on data performance of the system decreases as the CPU is not utilized properly, it may remain idle for some time. In order to minimize this time gap new segment of memory is Introduced known as Cache Memory.
Primary Memory
Primary storage or memory is also known as the main memory, which is the part of the computer that stores current data, programs, and instructions. Primary storage is stored in the motherboard which results in the data from and to primary storage can be read and written at a very good pace.