How does cache memory primarily affect performance?

Cache memory primarily affects performance by decreasing access time to frequently used data. It serves as a high-speed storage area located close to the CPU, allowing for faster retrieval of data that is accessed repeatedly. When the CPU needs data, it first checks the cache before accessing the slower main memory (RAM). Because the cache is built from faster types of memory technology, such as static RAM (SRAM), it significantly reduces the time it takes to access data that the CPU frequently uses, thereby improving overall system performance.

The cache operates on the principle of locality of reference, which means that programs tend to access the same data or instructions multiple times in a short period. By maintaining copies of this frequently accessed data, cache memory helps to minimize the delays caused by accessing slower memory types, resulting in quicker processing times and enhanced efficiency.

The other options do not accurately represent the primary function of cache memory. For instance, cache memory does not permanently store all data, nor does it expand the physical size of memory or manage input/output devices. Its main role is to act as a high-speed intermediary that optimizes access times for the CPU.