Topic 6: Resource Management Flashcards
(27 cards)
Identify the resources that need to be managed within a computer system.
Primary memory, secondary storage, processor speed, bandwidth, screen resolution, disk storage, sound processor, graphcis processor, cache, network connectivity
Describe primary memory
Stores all processed data, instructions, and resulting data. Directly connected to the processor. Can be considered as an addressable matrix of cells with a unique address for each and every cell. RAM, cache, and ROM are types of primary memory.
Distinguish between static RAM and dynamic RAM.
Static RAM holds data as long as there is a power supply to the memory circuits. It is faster, but more expensive than dynamic memory. It used for CPU cache memory. Dynamic RAM needs to be refreshed periodically, and is slower and cheaper than static RAM. It is the primary technology used to build RAM chips in modern PCs.
Describe ROM
Read-only-memory. Non-volatile (persists after power is lost). Often used to hold the Basic Input Output System (BIOS) which makes it possible for the PC to boot.
Describe secondary storage.
Hardware that provides low cost, mass storage capacity, and persistent storage. Can be grouped into two broad types: (1) direct access (hard-disks, SSDs, DVDs) which have the ability to access, retrieve and store any particular data without having to read through all previous data and (2) sequential access (magnetic tapes) which have to read through all previous data before locating the requested data.
Define clock rate
The frequency at which a processor is running, commonly measured in gigahertz (GHz)
Define memory bandwidth
The rate at which data can travel from SRAM and DRAM to the processor and vice-versa. Usually expressed in millions of bits per second (Mb/s).
Define screen resolution.
The number of distinct pixels that can be used to display videos, pictures, etc.
Describe disk storage
The general category of metal or plastic storage plates on which data can be recorded. Include hard disk drives (HDD, slower but cheaper) the floppy disk drive (FDD), various optical drives, solid state drives (SSD, faster but more expensive).
Describe a sound processor
Converts sound data between analog and digital formats. Usually built into motherboards, but dedicated high-quality sound cards exist for audio professionals.
Describe the graphics processor
Massively parallel processors, very efficient at manipulating and processing graphics and images. Some CPUs have integrated GPUs built in, while others are often sold as separate, dedicated cards.
Describe a network interface card (NIC)
Connects a computer to a network, may be wired or wireless, or even enable connectivity with mobile networks.
Evaluate the resources available to a “mainframe” supercomputer.
Used by large organizations for critical applications, large bandwidth communication and bulk data processing. Equipped with great processing power, vasts amounts of RAM, arrays of disks and backups.
Evaluate the resources available to a web server.
Provides a service to various clients, such as hosting a web page. Need multiple network connections, large amounts of RAM to support multiple requests, ease of repair without the need to shut down, back up facilities.
Identify the limitations of a range of resources in a specified computer system.
For example, In computer-generated imagery (CGI) the rendering process requires high performance computing system called “rendering farms”. A single processor computer may not be able to effectively render 3D graphics effectively.
Describe the possible problems resulting from the limitations in the resources in computer systems.
For example, user time is wasted if the primary memory is too small or processor speed inadequate.
Consider multi-access (multiple users can access a single computer) and multi-programming (more than one program can be loaded into main memory at a time) environments.
Explain the role of the operating system in terms of managing memory.
The OS is responsible for allocating and dellocating memory as programs are launched and quit. OS tracks the locations of programs within RAM and convert logical addresses into physical addresses. Address binding is the process of mapping a logical address to a physical address.
Explain the role of the OS in managing peripherals.
The OS uses a program called a device driver to handle all internal and external hardware, input and output peripherals and storage devices.
Explain how the OS manages hardware interfaces.
The OS provides an interface for other software to access hardware resources. For example, programs that want to allocate memory or access a peripheral make a request to the OS.
Outline how the OS manages resources: scheduling.
The processor scheduler decides on the next task admitted to the CPU and thus which process to run. The scheduling criteria that affect the selection of the best scheduling algorithm for a particular situation include CPU utilization, throughput, turnaround time, waiting time and response time.
Outline how the OS manages resources: policies.
The OS allows different user accounts to be set up with different priveleges and access rights of a particular user.
Outline how the OS manages resources: interrupts
An interrupt is a signal from a device or program that causes the OS to stop its current task and decide what to do next. Various interrupts are generated and have different priorities.
Outline how the OS manages resources: polling
The periodic checking of devices to sample their status. The CPU periodically checks certain registers, actuators, or sensors to see if the request has been made.
Outline how the OS manages resources: virutal memory and paging
Pagining allows the OS to implement virtual memory, allowing it to use secondary storage as if it was RAM. The OS copies as much data as it can to RAM, leaving the rest on disk. When the OS needs data from the disk, it exchanges a “page” of memory between RAM and disk.
