Cachehukommelse

Cache memory, or cachehukommelse in Danish, is a small, fast type of computer memory that is much faster than the main memory (RAM). It acts as a buffer between the processor and the main memory, storing frequently accessed data and instructions. The goal of cache memory is to reduce the average time it takes for the processor to access data from main memory.

When the processor needs to retrieve data, it first checks the cache. If the data is present in the cache, it is called a cache hit, and the data is retrieved very quickly. If the data is not in the cache, it is called a cache miss, and the processor has to fetch the data from the slower main memory. This data is then also copied into the cache, in anticipation that it might be needed again soon.

Cache memory is typically implemented using static random-access memory (SRAM) technology, which is faster and more expensive than the dynamic random-access memory (DRAM) used for main memory. Due to its cost, cache memory is usually much smaller in size compared to main memory.

Computers often have multiple levels of cache memory, known as L1, L2, and L3 cache. L1 cache is the smallest and fastest, located directly on the processor core. L2 cache is larger and slightly slower, and L3 cache is the largest and slowest of the cache levels, often shared among multiple processor cores. This hierarchical structure optimizes performance by providing quick access to the most frequently used data at the fastest levels.