Cache memory (pronounced money) is extremely fast memory that is either built into the computer’s central processing unit (CPU) or located next to it on a separate chip. Cache memory is used by the CPU to store instructions that are repeatedly needed to run programs, which improves overall system speed. The advantage of cache memory is that the CPU does not need to use the motherboard’s system bus for data transfer. Every time data must pass through the system bus, the data transfer speed is reduced to the capacity of the motherboard. The CPU can process data much faster, bypassing the bottleneck created by the system bus.
Cache memory is used by the CPU to improve the overall speed of a computer system.
It turns out that once most programs are up and running, they use very little resources. When these resources are cached, programs can operate faster and more efficiently. All things being equal, caching is so effective at system performance that a computer running a fast CPU with little cache can have lower benchmarks than a system running a slightly slower CPU with more cache. The cache built into the CPU itself is known as the level 1 (L1) cache. The cache that resides on a separate chip near the CPU is called a level 2 (L2) cache. Some CPUs have built-in L1 and L2 cache and designate the separate cache chip as level 3 (L3) cache.
ram card
The cache built into the CPU is faster than the separate cache and runs at the speed of the microprocessor itself. However, independent cache memory is still almost twice as fast as random access memory (RAM). Cache is more expensive than RAM, but it’s worth buying a CPU and motherboard with built-in cache to maximize system performance.
Disk caching applies the same principle to the hard drive that memory caching applies to the CPU. Frequently accessed hard drive data is stored in a separate segment of RAM to avoid the need to continuously retrieve it from the hard drive. In this case, RAM is faster than the platter technology used in conventional hard drives. However, this situation will change as hybrid hard drives become ubiquitous. These drives have built-in flash memory caches. Over time, hard drives will be 100% flash drives, which will eliminate the need for RAM disk caching, since flash memory is faster than RAM.
