Motherboard

A motherboard (sometimes alternatively known as the mainboard, system board,planar board or logic board,^[1] or colloquially, a mobo) is the main printed circuit board (PCB) found in computers and other expandable systems. It holds many of the crucial electronic components of the system, such as the central processing unit(CPU) and memory, and provides connectors for other peripherals. Unlike abackplane, a motherboard contains significant sub-systems such as the processor and other components.

Motherboard specifically refers to a PCB with expansion capability and as the name suggests, this board is the "mother" of all components attached to it, which often include sound cards, video cards, network cards, hard drives, or other forms of persistent storage; TV tuner cards, cards providing extra USB or FireWire slots and a variety of other custom components (the term mainboard is applied to devices with a single board and no additional expansions or capability, such as controlling boards in televisions, washing machines and other embedded systems).

Hardisk

"Hard drive" redirects here. For other uses, see Hard drive (disambiguation).

Hard disk drive

A 2.5" SATA hard drive
Date invented	24 December 1954[a]
Invented by	IBM team led by Rey Johnson

A disassembled and labeled 1997 HDD laying atop a mirror.
Overview of how an HDD functions
A hard disk drive (HDD)^[b] is a data storage device used for storing and retrieving digital information using rapidly rotating disks (platters) coated with magnetic material.^[2] An HDD retains its data even when powered off. Data is read in a random-access manner, meaning individual blocks of data can be stored or retrieved in any order rather than sequentially. An HDD consists of one or more rigid ("hard") rapidly rotating disks (platters) with magnetic headsarranged on a moving actuator arm to read and write data to the surfaces.
Introduced by IBM in 1956,^[3] HDDs became the dominant secondary storagedevice for general purpose computers by the early 1960s. Continuously improved, HDDs have maintained this position into the modern era of serversand personal computers. More than 200 companies have produced HDD units, though most current units are manufactured by Seagate, Toshiba and Western Digital. Worldwide disk storage revenues were US $32 billion in 2013, down 3% from 2012.^[4]
The primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes corresponding to powers of 1000: a 1-terabyte (TB) drive has a capacity of 1,000 gigabytes (GB; where 1 gigabyte = 1 billion bytes). Typically, some of an HDD's capacity is unavailable to the user because it is used by the file system and the computer operating system, and possibly inbuilt redundancy forerror correction and recovery. Performance is specified by the time to move the heads to a file (Average Access Time) plus the time it takes for the file to move under its head (average latency, a function of the physical rotational speed inrevolutions per minute) and the speed at which the file is transmitted (data rate).
The two most common form factors for modern HDDs are 3.5-inch in desktop computers and 2.5-inch in laptops. HDDs are connected to systems by standardinterface cables such as SATA (Serial ATA), USB or SAS (Serial attached SCSI) cables.
As of 2014, the primary competing technology for secondary storage is flash memory in the form of solid-state drives (SSDs). HDDs are expected to remain the dominant medium for secondary storage due to predicted continuing advantages in recording capacity, price per unit of storage, write latency and product lifetime.^[5][6] However, SSDs are replacing HDDs where speed, power consumption and durability are more important considerations.^[7][8]

Random Access Memory

Random-access memory (RAM /ræm/) is a form of computer data storage. A random-access memory device allows data items to be read and written in roughly the same amount of time regardless of the order in which data items are accessed.[1] In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement delays.

Today, random-access memory takes the form of integrated circuits. Strictly speaking, modern types of DRAM are not random access, as data is read in bursts, although the name DRAM / RAM has stuck. However, many types of SRAM are still random access even in a strict sense. RAM is normally associated with volatile types of memory (such as DRAM memory modules), where stored information is lost if the power is removed, although many efforts have been made to develop non-volatile RAM chips.[2] Other types of non-volatile memory exist that allow random access for read operations, but either do not allow write operations or have limitations on them. These include most types of ROM and a type of flash memory called NOR-Flash.

Integrated-circuit RAM chips came into the market in the late 1960s, with the first commercially available DRAM chip, the Intel 1103, introduced in October 1970.[3]sing the Solo (single-core), Duo (dual-core), Quad (quad-core), and in 2007, the Extreme (dual- or quad-core CPUs for enthusiasts) subbrands.[3] Intel Core 2 processors with vPro technology (designed for businesses) include the dual-core and quad-core branches.[4]

Intel Core 2

Intel Core 2 is a brand encompassing a range of Intel's consumer 64-bit x86-64 single-, dual-, and quad-core microprocessors based on the Core microarchitecture. The single- and dual-core models are single-die, whereas the quad-core models comprise two dies, each containing two cores, packaged in a multi-chip module.[1] The introduction of Core 2 relegated the Pentium brand to the mid-range market, and reunified laptop and desktop CPU lines, which previously had been divided into the Pentium 4, Pentium D, and Pentium M brands.

The Core 2 brand was introduced on 27 July 2006,[2] comprising the Solo (single-core), Duo (dual-core), Quad (quad-core), and in 2007, the Extreme (dual- or quad-core CPUs for enthusiasts) subbrands.[3] Intel Core 2 processors with vPro technology (designed for businesses) include the dual-core and quad-core branches.[4]