Basic concepts.md (797B)
1 +++ 2 title = 'Basic concepts' 3 +++ 4 # Basic concepts 5 maximum size of memory depends on the addressing scheme 6 7 memory access time — time elapsed between start of transfer of word of data and completion 8 9 memory cycle time — minimum time delay required between initiation of two successive memory operations 10 11 RAM (random-access memory) — memory where access time to any location is the same (compare to serial access) 12 13 ## Cache & virtual memory 14 memory access time is the bottleneck in the system. options to speed this up: 15 16 - cache memory — small, fast memory between main memory and processor 17 - virtual memory — only active portions of program are in main memory, remainder is on a secondary storage device 18 19 data is transferred between memories in blocks involving tens to thousands of words