: How does CPU Cache affect performance?
In: Technology
your computer can store its short term memory in 2 places, RAM or Cache. Cache is right next to the CPU, but small, think of it like a notepad.
RAM is far from the CPU, but large, think of it like a bookshelf.
When your CPU wants to do ANYTHING it needs to use some short term memory. Its kinda slow to get up and go to the bookshelf for everything, so its faster to use cache (the little notepad), but since it is a little notepad, it fills up quickly.
So larger faster Cache lets a CPU spend less time checking RAM than slow small Cache would
The main memory in a computer is slow compared to the processor in the computer. When the processor issues a command to the memory to give it some data it can take tens or hundreds of processor cycles for the requested data to arrive to the processor.
But once the memory starts sending data it can return a bunch of data all in one go. So to mitigate the delay on receiving data, and because most memory accesses are sequential, the processor requests a big chunk of sequential data from the memory in one go and stores it in its own internal super fast memory bank called a cache.
The bigger the cache, the less often the processor has to ask the main memory for data, and the less often the processor gets stuck waiting on the main memory.
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