Escalate Topic

The basic components of laptops function identically to their desktop counterparts. Traditionally they were miniaturized and adapted to mobile use, although desktop systems increasingly use the same smaller, lower-power parts which were originally developed for mobile use. The design restrictions on power, size, and cooling of laptops limit the maximum performance of laptop parts compared to that of desktop components, although that difference has increasingly narrowed.[27]

In general, laptop components are not intended to be replaceable or upgradable, with the exception of components which can be detached, such as a battery or CD/CDR/DVD drive. This restriction is one of the major differences between laptops and desktop computers, because the large "tower" cases used in desktop computers are designed so that new motherboards, hard disks, sound cards, RAM, and other components can be added. In a very compact laptop, such as laplets, there may be no upgradeable components at all.[28]

Intel, Asus, Compal, Quanta, and some other laptop manufacturers have created the Common Building Block standard for laptop parts to address some of the inefficiencies caused by the lack of standards and inability to upgrade components.[29]

The following sections summarizes the differences and distinguishing features of laptop components in comparison to desktop personal computer parts.[30]

Display[edit]
Most modern laptops feature a 13 inches (33 cm) or larger color active matrix display based on LED lighting with resolutions of 1280×800 (16:10) or 1366×768 (16:9) pixels and above. Models with LED-based lighting offer lesser power consumption, and often increased brightness. Netbooks with a 10 inches (25 cm) or smaller screen typically use a resolution of 1024×600, while netbooks and subnotebooks with a 11.6 inches (29 cm) or 12 inches (30 cm) screen use standard notebook resolutions. Having a higher resolution display allows more items to fit onscreen at a time, improving the user's ability to multitask, although at the higher resolutions on smaller screens, the resolution may only serve to display sharper graphics and text rather than increasing the usable area. Since the introduction of the MacBook Pro with Retina display in 2012, there has been an increase in the availability of very-high resolution (1920×1080 and higher) displays, even in relatively small systems, and in typical 15-inch screens resolutions as high as 3200×1800 are available. External displays can be connected to most laptops, and models with a Mini DisplayPort can handle up to three.[31]

Central processing unit[edit]
A laptop's central processing unit (CPU) has advanced power-saving features and produces less heat than one intended purely for desktop use. Typically, laptop CPUs have two processor cores, although 4-core models are also available. For low price and mainstream performance, there is no longer a significant performance difference between laptop and desktop CPUs, but at the high end, the fastest 4-to-8-core desktop CPUs still substantially outperform the fastest 4-core laptop processors, at the expense of massively higher power consumption and heat generation; the fastest laptop processors top out at 56 watts of heat, while the fastest desktop processors top out at 150 watts.

There have been a wide range of CPUs designed for laptops available from both Intel, AMD, and other manufacturers. On non-x86 architectures, Motorola and IBM produced the chips for the former PowerPC-based Apple laptops (iBook and PowerBook). Many laptops have removable CPUs, although this has become less common in the past few years as the trend has been towards thinner and lighter models. In other laptops the CPU is soldered on the motherboard and is non-replaceable; this is nearly universal in ultrabooks.

In the past, some laptops have used a desktop processor instead of the laptop version and have had high performance gains at the cost of greater weight, heat, and limited battery life, but the practice was largely extinct as of 2013. Unlike their desktop counterparts, laptop CPUs are nearly impossible to overclock. A thermal operating mode of laptops is very close to its limits and there is almost no headroom for an overclocking–related operating temperature increase. The possibility of improving a cooling system of a laptop to allow overclocking is extremely difficult to implement.

Graphical processing unit[edit]
On most laptops a graphical processing unit (GPU) is integrated into the CPU to conserve power and space. This was introduced by Intel with the Core i-series of mobile processors in 2010, and similar APU processors by AMD later that year. Prior to that, lower-end machines tended to use graphics processors integrated into the system chipset, while higher end machines had a separate graphics processor. In the past, laptops lacking a separate graphics processor were limited in their utility for gaming and professional applications involving 3D graphics, but the capabilities of CPU-integrated graphics have converged with the low-end of dedicated graphics processors in the past few years. Higher-end laptops intended for gaming or professional 3D work still come with dedicated, and in some cases even dual, graphics processors on the motherboard or as an internal expansion card. Since 2011, these almost always involve switchable graphics so that when there is no demand for the higher performance dedicated graphics processor, the more power-efficient integrated graphics processor will be used. Nvidia Optimus is an example of this sort of system of switchable graphics.

Memory[edit]
Most laptops use SO-DIMM (small outline dual in-line memory module) memory modules, as they are about half the size of desktop DIMMs.[30] They are sometimes accessible from the bottom of the laptop for ease of upgrading, or placed in locations not intended for user replacement. Most laptops have two memory slots, although some of the lowest-end models will have only one, and some high end models (usually mobile engineering workstations and a few high-end models intended for gaming) have four slots. Most mid-range laptops are factory equipped with 4–6 GB of RAM. Netbooks are commonly equipped with only 1–2 GB of RAM and are generally only expandable to 2 GB, if at all. Due to the limitation of DDR3 SO-DIMM of a maximum of 8 GB per module, most laptops can only be expanded to a total of 16 GB of memory, until systems using DDR4 memory start becoming available. Laptops may have memory soldered to the motherboard to conserve space, which allows the laptop to have a thinner chassis design. Soldered memory cannot be upgraded.

Internal storage[edit]
Traditionally, laptops had a hard disk drive (HDD) as a main non-volatile storage, but these proved inefficient for use in mobile devices due to high power consumption, heat production, and a presence of moving parts, which can cause damage to both the drive itself and the data stored when a laptop is unstable physically, e.g. during its use while transporting it or after its accidental drop. With the advent of flash memory technology, most mid- to high-end laptops opted for more compact, power efficient, and fast solid-state drives (SSD), which eliminated the hazard of drive and data corruption caused by a laptop's physical impacts.[32] Most laptops use 2.5-inch drives, which are a smaller version of a 3.5-inch desktop drive form factor. 2.5-inch HDDs are more compact, power efficient, and produce less heat, while at the same time have a smaller capacity and a slower data transfer rate. Some very compact laptops support even smaller 1.8-inch HDDs. For SSDs, however, these miniaturization-related trade-offs are nonexistent, because SSDs were designed to have a very small footprint. SSDs feature a traditional 2.5- or 1.8-inch or a laptop-specific mSATA or M.2 card's form factor. SSDs have a higher data transfer rate, lower power consumption, lower failure rate, and a larger capacity[33][34][35][36] compared to HDDs. However, HDDs have a significantly lower cost.

Most laptops can contain a single 2.5-inch drive, but a small number of laptops with a screen wider than 17 inches can house two drives. Some laptops support a hybrid mode, combining a 2.5-inch drive, typically a spacious HDD for data, with an mSATA or M.2 SDD drive, typically having less capacity, but a significantly faster read/write speed. The operating system partition would be located on the SSD to increase laptop I/O performance. Another way to increase performance is to use a smaller SSD of 16-32 GB as a cache drive with a compatible OS. Some laptops may have very limited drive upgradeability when the SSD used has a non-standard shape and/or requires a proprietary daughter card.[37] Some laptops have very limited space on the installed SSD, instead relying on availability of cloud storage services for storing of user data; Chromebooks are a prominent example of this approach. A variety of external HDDs or NAS data storage servers with support of RAID technology can be attached to virtually any laptop over such interfaces as USB, FireWire, eSATA, or Thunderbolt, or over a wired or wireless network to further increase space for the storage of data. Many laptops also incorporate a card reader which allows for use of memory cards, such as those used for digital cameras, which are typically SD or microSD cards. This enables users to download digital pictures from an SD card onto a laptop, thus enabling them to delete the SD card's contents to free up space for taking new pictures.

Removable media drive[edit]
Optical disc drives capable of playing CD-ROMs, compact discs (CD), DVDs, and in some cases, Blu-ray Discs (BD), were nearly universal on full-sized models in the 2010s. A disc drive remains fairly common in laptops with a screen wider than 15 inches (38 cm), although the trend towards thinner and lighter machines is gradually eliminating these drives and players; these drives are uncommon in compact laptops, such as subnotebooks and netbooks. Laptop optical drives tend to follow a standard form factor, and usually have a standard mSATA connector. It is often possible to replace an optical drive with a newer model. In certain laptop models there is a possibility to replace an optical drive with a second hard drive, using a caddy that fills the extra space the optical drive would have occupied.

Inputs[edit]

Closeup of a touchpad on an Acer laptop
An alphanumeric keyboard is used to enter text and data and make other commands (e.g., function keys). A touchpad (also called a trackpad), a pointing stick, or both, are used to control the position of the cursor on the screen, and an integrated keyboard[38] is used for typing. An external keyboard and/or mouse may be connected using a USB port or wirelessly, via Bluetooth or similar technology. With the advent of ultrabooks and support of touch input on screens by 2010-era operating systems, such as Windows 8.1, multitouch touchscreen displays are used in many models. Some models have webcams and microphones, which can be used to communicate with other people with both moving images and sound, via Skype, Google Chat and similar software. Laptops typically have USB ports and a microphone jack, for use with an external mic. Some laptops have a card reader for reading digital camera SD cards.

Input/output (I/O) ports[edit]
On a typical laptop there are several USB ports, an external monitor port (VGA, DVI, HDMI or Mini DisplayPort), an audio in/out port (often in form of a single socket) is common. It is possible to connect up to three external displays to a 2014-era laptop via a single Mini DisplayPort, utilizing multi-stream transport technology.[31] Apple, in a 2015 version of its MacBook, transitioned from a number of different I/O ports to a single USB Type-C port.[39] This port can be used both for charging and connecting a variety of devices through the use of aftermarket adapters. Google, with its updated version of Chromebook Pixel, shows a similar transition trend towards USB Type-C, although keeping older USB Type-A ports for a better compatibility with older devices.[40] Although being common until the end of the 2000s decade, Ethernet network port are rarely found on modern laptops, due to widespread use of wireless networking, such as Wi-Fi. Legacy ports such as a PS/2 keyboard/mouse port, serial port, parallel port, or Firewire are provided on some models, but they are increasingly rare. On Apple's systems, and on a handful of other laptops, there are also Thunderbolt ports, but Thunderbolt 3 uses USB Type-C. Laptops typically have a headphone jack, so that the user can connect external headphones or amplified speaker systems for listening to music or other audio.