A computer’s memory hierarchy organizes storage into levels with different response times, capacities, and technologies. Understanding this arrangement helps explain why some data can be accessed quickly while other data takes longer to retrieve.
A memory hierarchy is a sequence of storage components arranged according to characteristics such as response time, capacity, complexity, and performance. In general, faster storage is smaller and more expensive per unit of capacity, while slower storage offers more capacity.
All flashcards
What is a memory hierarchy?
An organization of computer storage into levels that differ in response time, capacity, performance, and controlling technologies.
What is the usual speed-and-size relationship between adjacent hierarchy levels?
A level is typically faster and smaller than the next lower level. Faster storage offers quick access but usually has less capacity.
What are the four broad storage levels?
Internal storage (registers and cache), main storage (RAM and controller cards), online mass storage (secondary storage), and offline bulk storage (tertiary and offline storage).
How do online, nearline, and offline storage differ?
Online storage is immediately available for I/O. Nearline storage can be made available quickly without human intervention. Offline storage requires human intervention to bring it online.
What do latency and bandwidth describe, and are they uniform across the hierarchy?
Latency describes access or transfer delay, while bandwidth describes the amount of data transferred over time. Neither is uniform; each component has its own characteristics.
Quiz questions
What does memory tiering do with memory that has different performance characteristics?Answer: It organizes memory into performance levels and moves contents between them.
What can happen when register pressure exceeds the available register capacity?Answer: Register spilling moves values from registers to cache.
Which components are classified as internal storage in the broad four-level classification?Answer: Processor registers and cache.
A tape cartridge is loaded automatically by a library when requested. How is its availability classified?Answer: Nearline, because it can be brought online quickly without human intervention.
What is a hard page fault when a program needs data that is not in real main memory?Answer: The data must be brought from virtual memory on mass storage into real memory.
Based on the Wikipedia article Memory hierarchy, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.