Misplaced Pages

#278721

74-488: To conserve power and manage heat, many laptop and desktop processors have a power management feature that software (usually the operating system ) can use to adjust the clock speed and core voltage dynamically . Often a voltage regulator module converts from 5V or 12 V or some other voltage to whatever CPU core voltage is required by the CPU. The trend is towards lower core voltages, which conserve power. This presents

148-447: A hard disk drive (HDD) for storage; since then, solid-state drives (SSD) have gradually come to supplant hard drives in all but some inexpensive consumer models. Solid-state drives are faster and more power-efficient, as well as eliminating the hazard of drive and data corruption caused by a laptop's physical impacts, as they use no mechanical parts such as a rotational platter. In many cases, they are more compact as well. Initially, in

222-406: A laptop or notebook , is a small, portable personal computer (PC). Laptops typically have a clamshell form factor with a flat-panel screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid. Most of the computer's internal hardware is fitted inside the lower lid enclosure under the keyboard, although many modern laptops have

296-417: 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 since the mid-2010s. For laptops possessing limited onboard graphics capability but sufficient I/O throughput, an external GPU (eGPU) can provide additional graphics power at

370-414: A broad range of devices, which combined features of several previously separate device types. The hybrids , convertibles , and 2-in-1s emerged as crossover devices, which share traits of both tablets and laptops. All such devices have a touchscreen display designed to allow users to work in a tablet mode, using either multi-touch gestures or a stylus / digital pen . Convertibles are devices with

444-429: A built-in webcam at the top of the screen, and some even feature a touchscreen display. In most cases, unlike tablet computers which run on mobile operating systems , laptops tend to run on desktop operating systems, which were originally developed for desktop computers . The word laptop , modeled after the term desktop (as in desktop computer ), refers to the fact that the computer can be practically placed on

518-502: A digital circuit can switch states - that is, to go from "low" ( VSS ) to "high" ( VDD ) or vice versa - is proportional to the voltage differential in that circuit. Reducing the voltage means that circuits switch slower, reducing the maximum frequency at which that circuit can run. This, in turn, reduces the rate at which program instructions that can be issued, which may increase run time for program segments which are sufficiently CPU-bound. This again highlights why dynamic voltage scaling

592-458: A few high-end models intended for gaming do as well. As of 2021, 8 GB RAM is most common, with lower-end models occasionally having 4 GB. Higher-end laptops may come with 16 GB of RAM or more. The earliest laptops most often used floppy disk for storage, although a few used either RAM disk or tape, by the late 1980s hard disk drives had become the standard form of storage. Between 1990 and 2009, almost all laptops typically had

666-405: A full-featured desktop OS like Windows 10 , and have a number of typical laptop I/O ports, such as USB 3 and Mini DisplayPort . 2-in-1s are designed to be used not only as a media consumption device but also as valid desktop or laptop replacements, due to their ability to run desktop applications, such as Adobe Photoshop . It is possible to connect multiple peripheral devices, such as

740-592: A laptop and provide display output over one USB-C Cable. Most laptop displays have a maximum refresh rate of 60 Hz. The Dell M17x and Samsung 700G7A, both released in 2011, were among the first laptops to feature a 120 Hz refresh rate, and more such laptops have appeared in the years since. A laptop's CPU has advanced power-saving features and produces less heat than one intended purely for desktop use. Mainstream laptop CPUs made after 2018 have at least two processor cores, often four cores, and sometimes more, with 6 and 8 cores becoming more common. For

814-516: A mouse, keyboard, and several external displays to a modern 2-in-1. Microsoft Surface Pro-series devices and Surface Book are examples of modern 2-in-1 detachable, whereas Lenovo Yoga -series computers are a variant of 2-in-1 convertibles. While the older Surface RT and Surface 2 have the same chassis design as the Surface Pro, their use of ARM processors and Windows RT do not classify them as 2-in-1s, but as hybrid tablets. Similarly,

SECTION 10

#1732779586279

888-742: A number of hybrid laptops run a mobile operating system , such as Android . These include Asus's Transformer Pad devices, examples of hybrids with a detachable keyboard design, which do not fall in the category of 2-in-1s. A rugged laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures, and wet or dusty environments. Rugged laptops are bulkier, heavier, and much more expensive than regular laptops, and thus are seldom seen in regular consumer use. The basic components of laptops function identically to their desktop counterparts. Traditionally they were miniaturized and adapted to mobile use, The design restrictions on power, size, and cooling of laptops limit

962-450: A single CPU package. However, despite the overall reduction in transistor size, not all voltage requirements scale down proportionally. Some components within the CPU may still require higher voltages to operate efficiently, necessitating the use of multiple voltage levels to power various components effectively. Some examples of different voltages in a modern CPU: Laptop A laptop computer or notebook computer , also known as

1036-470: A single power voltage throughout the chip, supplying both I/O power and internal power. All CPUs before the Pentium MMX are single-voltage CPUs. Dual-voltage CPUs were introduced for performance gain when increasing clock speeds and finer semiconductor fabrication processes caused excess heat generation and power supply concerns, especially regarding laptop computers . Using a voltage regulator ,

1110-485: A small niche market , mostly for specialized field applications, such as in the military, for accountants, or travelling sales representatives. As portable computers evolved into modern laptops, they became widely used for a variety of purposes. The history of the laptop follows closely behind the development of the personal computer itself. A "personal, portable information manipulator" was imagined by Alan Kay at Xerox PARC in 1968, and described in his 1972 paper as

1184-496: A standard for memory cards in PCs. The specification for PCMCIA type I cards, later renamed PC Cards, was first released in 1990. Displays reached 640x480 ( VGA ) resolution by 1988 ( Compaq SLT/286 ), and color screens started becoming a common upgrade in 1991, with increases in resolution and screen size occurring frequently until the introduction of 17" screen laptops in 2003. Hard drives started to be used in portables, encouraged by

1258-556: A typical Pentium processor with both I/O and core voltage at 3.3V. All Pentium MMX and later processors adopted this so-called split rail power supply. Besides CPU core voltage, modern CPUs often have many different voltages for components. One of the reasons behind this was that modern CPUs integrate numerous components that were once separate integrated circuits (ICs). As semiconductor technology has advanced, functions such as CPU cores, memory controllers, PCIe controllers, and, in some cases, integrated graphics, have been consolidated into

1332-439: 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 ). Between around 2000 to 2014, most full-size laptops had socketed, replaceable CPUs; on thinner models, the CPU was soldered on the motherboard and was not replaceable or upgradable without replacing

1406-462: Is α ⋅ C ⋅ V 2 ⋅ f {\displaystyle \alpha \cdot C\cdot V^{2}\cdot f} , where C {\displaystyle C} is the capacitance being switched per clock cycle, V {\displaystyle V} is the supply voltage , f {\displaystyle f} is the switching frequency, and α {\displaystyle \alpha }

1480-398: Is a concept for a laptop that can be easily disassembled. The terms laptop and notebook both trace their origins to the early 1980s, coined to describe portable computers in a size class smaller than the contemporary mainstream units (so-called "luggables" ) but larger than pocket computers . The etymologist William Safire traced the origin of laptop to some time before 1984;

1554-441: Is also used to refer to increasing static operating voltage of computer components to allow operation at higher speed ( overclocking ). MOSFET -based digital circuits operate using voltages at circuit nodes to represent logical state. The voltage at these nodes switches between a high voltage and a low voltage during normal operation—when the inputs to a logic gate transition, the transistors making up that gate may toggle

SECTION 20

#1732779586279

1628-570: Is for long channel MOSFETs. With the area of the MOSFETs halving every 18-24 months ( Moore's law ) the distance between the two terminals of the MOSFET switch called the channel length is becoming smaller and smaller. This changes the nature of the relationship between terminal voltages and current. Overclocking a processor increases its clock speed at the cost of system stability. Withstanding higher clock speeds often requires higher core voltage at

1702-505: Is generally done in conjunction with dynamic frequency scaling, at least for CPUs. There are complex tradeoffs to consider, which depend on the particular system, the load presented to it, and power management goals. When quick responses are needed (e.g. Mobile Sensors and Context-Aware Computing ), clocks and voltages might be raised together. Otherwise, they may both be kept low to maximize battery life. The 167-processor AsAP 2 chip enables individual processors to make extremely fast (on

1776-618: Is increased heat: the power dissipated by a circuit increases with the square of the voltage applied, so even small voltage increases significantly affect power. At higher temperatures, transistor performance is adversely affected, and at some threshold, the performance reduction due to the heat exceeds the potential gains from the higher voltages. Overheating and damage to circuits can occur very quickly when using high voltages. There are also longer-term concerns: various adverse device-level effects such as hot carrier injection and electromigration occur more rapidly at higher voltages, decreasing

1850-406: Is known as overvolting ; dynamic voltage scaling to decrease voltage is known as undervolting . Undervolting is done in order to conserve power , particularly in laptops and other mobile devices , where energy comes from a battery and thus is limited, or in rare cases, to increase reliability. Overvolting is done in order to support higher frequencies for performance . The term "overvolting"

1924-480: Is mounted, although, as of 2021, an increasing number of models use memory soldered to the motherboard, either alongside SO-DIMM slots or without any slots and soldering all memory to the motherboard, but a new form factor, the CAMM module , is slated to fix the size and timing limitation. Before 2000, most laptops used proprietary memory modules if their memory was upgradable. In the early 2010s, high end laptops such as

1998-429: Is no clear dividing line in minimum or maximum size. Machines small enough to be handheld (screens in the 6–8" range) can be marketed either as very small laptops or "handheld PCs", while the distinction between the largest laptops and "All-in-One" desktops is whether they fold for travel. Having a higher resolution display allows more items to fit onscreen at a time, improving the user's ability to multitask, although, at

2072-430: Is not unknown as of 2022, but since around 2010, the practice has been restricted to small-volume gaming models. Laptop CPUs are rarely able to be overclocked ; most use locked processors. Even on gaming models where unlocked processors are available, the cooling system in most laptops is often very close to its limits and there is rarely headroom for an overclocking–related operating temperature increase. On most laptops,

2146-557: Is the activity factor. Since V {\displaystyle V} is squared, this part of the power consumption decreases quadratically with voltage. The formula is not exact however, as many modern chips are not implemented using 100% CMOS, but also use special memory circuits, dynamic logic such as domino logic , etc. Moreover, there is also a static leakage current , which has become more and more accentuated as feature sizes have become smaller (below 90 nanometres) and threshold levels lower. Accordingly, dynamic voltage scaling

2220-586: Is widely used as part of strategies to manage switching power consumption in battery powered devices such as cell phones and laptop computers. Low voltage modes are used in conjunction with lowered clock frequencies to minimize power consumption associated with components such as CPUs and DSPs; only when significant computational power is needed will the voltage and frequency be raised. Some peripherals also support low voltage operational modes. For example, low power MMC and SD cards can run at 1.8 V as well as at 3.3 V, and driver stacks may conserve power by switching to

2294-588: The BIOS ). It is usually possible to control the voltages supplied to the CPU, RAM , PCI , and PCI Express (or AGP ) port through a PC's BIOS. However, some components do not allow software control of supply voltages, and hardware modification is required by overclockers seeking to overvolt the component for extreme overclocks. Video cards and motherboard northbridges are components which frequently require hardware modifications to change supply voltages. These modifications are known as "voltage mods" or "Vmod" in

CPU core voltage - Misplaced Pages Continue

2368-581: The Socket G2 , but many laptops use processors that are soldered to the motherboard. Many laptops come with RAM and storage that is soldered to the motherboard and cannot be easily replaced. 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. Memory and storage can often be upgraded with some disassembly, but with

2442-576: The flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85. The US$ 8,150 (equivalent to $ 25,730 in 2023) GRiD Compass 1101 , released in 1982, was used at NASA and by the military , among others. The Sharp PC-5000 , the Ampere WS-1 , and Gavilan SC were released between 1983 and 1985. The Toshiba T1100 won acceptance by PC experts and

2516-496: The input/output components and capabilities of a desktop computer into a single unit, including a display screen (usually 11–17 in or 280–430 mm in diagonal size), small speakers, a keyboard, and a pointing device (namely compact ones such as touchpads or pointing sticks ). Hardware specifications may vary significantly between different types, models, and price points . Design elements, form factors, and construction can also vary significantly between models depending on

2590-449: The lifespan of overvolted components. In order to mitigate the increased heat from overvolting, it's recommended to use liquid cooling to achieve higher ceilings and thresholds than you normally would with an aftermarket cooler. Also known as 'all-in-one' (AIO) coolers, they offer a far more effective method of unit cooling by relocating heat outside a computer case via the fans on the radiator whereas air cooling only disperses heat from

2664-589: The " Dynabook ". The IBM Special Computer APL Machine Portable (SCAMP) was demonstrated in 1973. This prototype was based on the IBM PALM processor . The IBM 5100 , the first commercially available portable computer , appeared in September 1975, and was based on the SCAMP prototype. As 8-bit CPU machines became widely accepted, the number of portables increased rapidly. The first "laptop-sized notebook computer"

2738-450: The 1970s introduction of portable computers, their forms have changed significantly, spawning a variety of visually and technologically differing subclasses. Excepting distinct legal trademark around terms (notably Ultrabook ), hard distinctions between these classes were rare, and their usage has varied over time and between sources. Since the late 2010s, more specific terms have become less commonly used, with sizes distinguished largely by

2812-427: The 1980s using red plasma displays could only be used when connected to AC power, and had a built in power supply. The development of memory cards was driven in the 1980s by the need for a floppy-disk-drive alternative, having lower power consumption, less weight, and reduced volume in laptops. The Personal Computer Memory Card International Association (PCMCIA) was an industry association created in 1989 to promote

2886-509: The 2011 Samsung 700G7A have passed the 10 GB RAM barrier, featuring 16 GB of RAM. When upgradeable, memory slots are sometimes accessible from the bottom of the laptop for ease of upgrading; in other cases, accessing them requires significant disassembly. Most laptops have two memory slots, although some will have only one, either for cost savings or because some amount of memory is soldered. Some high-end models have four slots; these are usually mobile engineering workstations, although

2960-643: The CMOS designer with a challenge, because in CMOS the voltages go only to ground and the supply voltage, the source, gate, and drain terminals of the FETs have only the supply voltage or zero voltage across them. The MOSFET formula: I D = k ( ( V G S − V t n ) V D S − ( V D S / 2 ) 2 ) {\displaystyle \,I_{D}=k((V_{GS}-V_{tn})V_{DS}-(V_{DS}/2)^{2})} says that

3034-404: The CPU frequencies (though limited to hardware capabilities). Dynamic frequency scaling is another power conservation technique that works on the same principles as dynamic voltage scaling. Both dynamic voltage scaling and dynamic frequency scaling can be used to prevent computer system overheating, which can result in program or operating system crashes , and possibly hardware damage. Reducing

CPU core voltage - Misplaced Pages Continue

3108-558: The 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, followed by similar AMD APU processors in January 2011. Before 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

3182-504: The MOSFET's threshold voltage. Additionally, the more the gate voltage exceeds the threshold voltage, the lower the resistance of the transistor's conducting channel. This results in a lower RC time constant for quicker charging and discharging of the capacitance of the subsequent logic stage. Quicker transitioning afforded by higher supply voltages allows for operating at higher frequencies. Many modern components allow voltage regulation to be controlled through software (for example, through

3256-470: The ability to conceal a hardware keyboard. Keyboards on such devices can be flipped, rotated, or slid behind the back of the chassis, thus transforming from a laptop into a tablet. Hybrids have a keyboard detachment mechanism, and due to this feature, all critical components are situated in the part with the display. 2-in-1s can have a hybrid or a convertible form, often dubbed 2-in-1 detachable and 2-in-1 convertibles respectively, but are distinguished by

3330-465: The ability to run a desktop OS , such as Windows 10 . 2-in-1s are often marketed as laptop replacement tablets . 2-in-1s are often very thin, around 10 millimetres (0.39 in), and light devices with a long battery life. 2-in-1s are distinguished from mainstream tablets as they feature an x86 -architecture CPU (typically a low- or ultra-low-voltage model), such as the Intel Core i5 , run

3404-581: The cost of physical space and portability. 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 and AMD Hybrid Graphics are examples of this sort of system of switchable graphics. Traditionally,

3478-462: The cost of power consumption and heat dissipation. This is called "overvolting" . Overvolting generally involves running a processor out of its specifications, which may damage it or shorten CPU life. A dual-voltage CPU uses a split-rail design so the processor core can use a lower voltage, while the external Input/Output ( I/O ) voltages remain at 3.3 volts (or 5 volts for older CPU's) for backwards compatibility. A single-voltage CPU uses

3552-592: The current I D {\displaystyle I_{D}} supplied by the FET is proportional to the gate-source voltage reduced by a threshold voltage V t n {\displaystyle V_{tn}} , which depends on the geometrical shape of the FET's channel and gate and their physical properties, especially capacitance . To reduce V t n {\displaystyle V_{tn}} (necessary to reduce supply voltage and increase current) one must increase capacitance. However,

3626-476: The earliest attestation of laptop found by the Oxford English Dictionary dates to 1983. The word is modeled after the term desktop , as in desktop computer . Notebook , meanwhile, emerged earlier in 1982 to describe Epson 's HX-20 portable, whose dimensions roughly correspond to a letter -sized pad of paper . Notebooks emerged as their own separate market from laptops with

3700-417: The early 2010s. Optical disc drives became common in full-size laptops around 1997: initially, CD-ROM drives, supplanted by CD-R, then DVD, then Blu-ray drives with writing capability. Starting around 2011, the trend shifted against internal optical drives, and as of 2022, they have largely disappeared, though are still readily available as external peripherals . In 2021, Dell showed Concept Luna, which

3774-488: The external I/O voltage levels were transformed to lower voltages to reduce power draw, resulting in less heat for the ability to operate at higher frequencies. VRT is a feature on older Intel P5 Pentium processors that are typically intended for use in a mobile environment. It refers to splitting the core voltage supply from the I/O voltage. A VRT processor has a 3.3 V I/O and 2.9 V core voltage, to save power compared to

SECTION 50

#1732779586279

3848-619: The gate's output. Toggling a MOSFET's state requires changing its gate voltage from below the transistor's threshold voltage to above it (or from above it to below it). However, changing the gate's voltage requires charging or discharging the capacitance at its node. This capacitance is the sum of capacitances from various sources: primarily transistor gate capacitance , diffusion capacitance , and wires ( coupling capacitance ). Higher supply voltages result in faster slew rate (rate of change of voltage per unit of time) when charging and discharging, which allows for quicker transitioning through

3922-769: 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 "HiDPI" (or high Pixel density ) displays; as of 2022, this is generally considered to be anything higher than 1920 pixels wide. This has increasingly converged around 4K (3840-pixel-wide) resolutions. External displays can be connected to most laptops, with most models supporting at least one. The use of technology such as USB4 (section Alternate Mode partner specifications ). DisplayPort Alt Mode has been utilized to charge

3996-650: The intended use. Examples of specialized models of laptops include 2-in-1 laptops , with keyboards that either be detached or pivoted out of view from the display (often marketed having a "laptop mode"); rugged laptops , for use in construction or military applications ; and low-production-cost laptops such as those from the One Laptop per Child (OLPC) organization, which incorporate features like solar charging and semi-flexible components not found on most laptop computers. Portable computers , which later developed into modern laptops, were originally considered to be

4070-469: The introduction of 3.5" drives in the late 1980s, and became common in laptops starting with the introduction of 2.5" and smaller drives around 1990; capacities have typically lagged behind those of physically larger desktop drives. Resolutions of laptop webcams are 720p (HD), or 480p in lower-end laptops. The earliest-known laptops with 1080p (Full HD) webcams, like the Samsung 700G7C, were released in

4144-495: The late 2000s, SSDs were substantially more expensive than HDDs, but as of 2021 prices on smaller capacity (under 1 terabyte ) drives have converged; larger capacity drives remain more expensive than comparable-sized HDDs. Dynamic voltage scaling In computer architecture , dynamic voltage scaling is a power management technique in which the voltage used in a component is increased or decreased, depending upon circumstances. Dynamic voltage scaling to increase voltage

4218-402: The load being driven is another FET gate, so the current it requires is proportional to capacitance, which thus requires the designer to keep capacitance low. The trend towards lower supply voltage therefore works against the goal of high clock speed. Only improvements in photolithography and reduction in threshold voltage allow both to improve at once. On another note, the formula shown above

4292-478: The 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 desktop CPUs still substantially outperform the fastest 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 (and often need water cooling). There has been

4366-487: The lower voltage after detecting a card which supports it. When leakage current is a significant factor in terms of power consumption, chips are often designed so that portions of them can be powered completely off. This is not usually viewed as being dynamic voltage scaling, because it is not transparent to software. When sections of chips can be turned off, as for example on TI OMAP3 processors, drivers and other support software need to support that. The speed at which

4440-560: The mass market as a way to have PC portability. From 1983 onward, several new input techniques were developed and included in laptops, including the touch pad ( Gavilan SC , 1983), the pointing stick (IBM ThinkPad 700 , 1992), and handwriting recognition (Linus Write-Top, 1987). Some CPUs, such as the 1990 Intel i386SL , were designed to use minimum power to increase the battery life of portable computers and were supported by dynamic power management features such as Intel SpeedStep and AMD PowerNow! in some designs. Some laptops in

4514-406: The maximum performance of laptop parts compared to that of desktop components, although that difference has increasingly narrowed. In general, laptop components are not intended to be replaceable or upgradable by the end-user, except for components that can be detached; in the past, batteries and optical drives were commonly exchangeable. Some laptops feature socketed processors with sockets such as

SECTION 60

#1732779586279

4588-479: The most compact laptops, there may be no upgradeable components at all. The following sections summarize the differences and distinguishing features of laptop components in comparison to desktop personal computer parts. The typical laptop has a screen that, when unfolded, is upright to the user. Laptop screens most commonly employ liquid-crystal display (LCD) technology, although use of OLED panels has risen substantially since 2020. The display interfaces with

4662-927: The motherboard using the embedded DisplayPort protocol via the Low-voltage differential signaling (LVDS) 30 or 40 pin connector. The panels are mainly manufactured by AU Optronics , BOE Technology , LG Display or Samsung Display . Externally, it can be a glossy or a matte (anti-glare) screen. In the past, there was a broader range of marketing terms (both formal and informal) to distinguish between different sizes of laptops. These included Netbooks , subnotebooks , Ultra-mobile PC , and Desktop replacement computers ; these are sometimes still used informally, although they are essentially dead in terms of manufacturer marketing. As of 2021, mainstream consumer laptops tend to come with 11", 13" or 15"-16" screens; 14" models are more popular among business machines. Larger and smaller models are available, but less common – there

4736-428: The motherboard. Since 2015, Intel has not offered new laptop CPU models with pins to be interchangeable, preferring ball grid array chip packages which have to be soldered; and as of 2021, only a few rare models using desktop parts. 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; this

4810-439: The order of 1-2ns) and locally controlled changes to their own supply voltages. Processors connect their local power grid to either a higher (VddHi) or lower (VddLow) supply voltage, or can be cut off entirely from either grid to dramatically cut leakage power. Another approach uses per-core on-chip switching regulators for dynamic voltage and frequency scaling (DVFS). Unix system provides a userspace governor, allowing to modify

4884-424: The overclocking community. Undervolting is reducing the voltage of a component, usually the processor, reducing temperature and cooling requirements, and possibly allowing a fan to be omitted. Just like overclocking, undervolting is highly subject to the so-called silicon lottery: one CPU can undervolt slightly better than the other and vice versa. The switching power dissipated by a chip using static CMOS gates

4958-481: The release of the NEC UltraLite in 1988. Notebooks and laptops continued to occupy distinct market segments into the mid-1990s, but ergonomic considerations and customer preference for larger screens soon led to notebooks converging with laptops in the late 1990s. Today, the terms laptop and notebook are synonymous, with laptop being the more common term in most English-speaking territories. Since

5032-432: The size of mainstream laptops has gone down and their capabilities have gone up; except for niche models, laptop sizes tend to be distinguished by the size of the screen, and for more powerful models, by any specialized purpose the machine is intended for, such as a " gaming laptop " or a " mobile workstation " for professional use. The latest trend of technological convergence in the portable computer industry spawned

5106-511: The size of the screen. There were in the past a number of marketing categories for smaller and larger laptop computers; these included "notebook" and " subnotebook " models, low cost " netbooks ", and " ultra-mobile PCs " where the size class overlapped with devices like smartphone and handheld tablets , and " Desktop replacement " laptops for machines notably larger and heavier than typical to operate more powerful processors or graphics hardware . All of these terms have fallen out of favor as

5180-418: The system RAM on laptops (as well as on desktop computers) was physically separate from the graphics memory used by the GPU. Apple's M series SoCs feature a unified pool of memory for both the system and the GPU; this approach can produce substantial efficiency gains for some applications but comes at the cost of eGPU support. Since around the year 2000, most laptops have used SO-DIMM slots in which RAM

5254-502: The time, but has since come to mean the same thing and no longer refers to any specific size. Laptops are used in a variety of settings, such as at work (especially on business trips ), in education , for playing games , web browsing , for personal multimedia , and for general home computer use. They can run on both AC power and rechargable battery packs and can be folded shut for convenient storage and transportation, making them suitable for mobile use . Laptops combine many of

5328-472: The user's lap ; while the word notebook refers to most laptops sharing a form factor with paper notebooks . As of 2024 , in American English , the terms laptop and notebook are used interchangeably; in other dialects of English , one or the other may be preferred. The term notebook originally referred to a type of portable computer that was smaller and lighter than mainstream laptops of

5402-475: The voltage supplied to the CPU below the manufacturer's recommended minimum setting can result in system instability. The efficiency of some electrical components, such as voltage regulators, decreases with increasing temperature, so the power used may increase with temperature causing thermal runaway . Increases in voltage or frequency may increase system power demands even faster than the CMOS formula indicates, and vice versa. The primary caveat of overvolting

5476-817: Was the Epson HX-20 , invented (patented) by Suwa Seikosha 's Yukio Yokozawa in July 1980, introduced at the COMDEX computer show in Las Vegas by Japanese company Seiko Epson in 1981, and released in July 1982. It had an LCD screen, a rechargeable battery, and a calculator-size printer, in a 1.6 kg (3.5 lb) chassis, the size of an A4 notebook . It was described as a "laptop" and "notebook" computer in its patent. Both Tandy/RadioShack and Hewlett-Packard (HP) also produced portable computers of varying designs during this period. The first laptops using

#278721