A history Of Ram Caches, prefetcher and superfetch!
Ever since the dawn of computing random access memory (RAM) has always been a limiting factor, it determines how much information the cpu can "juggle in the air" to keep a program open and to display its contents, early on programs were made to fit specific ram requirements (not to mention much earlier you only had around 600kb of base system memory to work with!!) because RAM was never cheap, at around 100$ for 4 megabytes (yes MegaBytes), windows 1.0 came and demanded for more, these where the days where you could only open 2 applications at much, before windows notified you ran out of memory! You could only run as many programs that the memory could handle
these two are too big for the system memory!