How Laptops Operate

It's somewhat ironic how the soaring popularity of laptops has unfolded. They're entirely portable, consume less power, and produce less noise compared to desktop computers. However, they tend to be slightly slower and offer lower graphics and sound processing capabilities, though these differences are often too subtle for most users to detect.

Laptops generally cost more than desktop computers, but the price gap is shrinking. Laptop prices are dropping faster than desktop prices, and for the first time in May of 2005, laptop PCs surpassed desktop sales [Source: Windows IT Pro].

How is it possible for all the components of a desktop tower to be compressed into such a compact device? And how do laptops manage to operate efficiently on just battery power? This article will answer these and many other questions about laptops.

In general, laptops and desktop computers share a lot of similarities. They both use the same fundamental hardware, software, and operating systems. The key distinction lies in how their components are organized and assembled.

A desktop computer typically contains a motherboard, video card, hard drive, and various other parts within a large case. The monitor, keyboard, and other peripherals are connected either wirelessly or with cables. Whether the case is oriented vertically or horizontally, it provides ample space for expansion cards, cables, and airflow.

A laptop, on the other hand, is much more compact and lightweight than even the smallest PC tower. Its screen and keyboard are integrated into the same unit. Instead of a spacious case with room for ventilation, a laptop features a slim, flat design where all components fit together tightly.

Due to this fundamental design difference, and because of a laptop’s inherent portability, its components must:

These design differences often make the components more costly, which can contribute to the higher price of laptops. In the next sections, we will explore how laptops manage these challenges.

Laptop Processors

The microprocessor, or CPU, collaborates with the operating system to manage the computer’s operations. It essentially serves as the brain of the computer. The CPU generates significant heat, so a desktop computer uses air circulation, a fan, and a heat sink—a set of plates, channels, and radiator fins designed to draw heat away from the processor—for cooling. Since a laptop offers limited space for these cooling systems, its CPU typically:

­

Some laptops use desktop CPUs that are configured to operate at lower clock speeds. While this can enhance performance, these laptops tend to generate more heat and experience a significant reduction in battery life.

Laptops typically feature small fans, heat sinks, heat spreaders, or heat pipes to help dissipate the heat produced by the CPU. Some premium laptop models further reduce heat with liquid coolant circulating in channels alongside the heat pipe. Additionally, most laptop CPUs are positioned near the edge of the unit, allowing the fan to expel the heat directly to the outside, rather than dispersing it across other components.

Laptop Memory and Storage

A laptop's memory can compensate for some of the performance loss caused by a slower processor. Certain laptops include cache memory located on or very close to the CPU, enabling faster data retrieval. Some laptops also feature larger busses, which facilitate quicker data transfer between the processor, motherboard, and memory.

Laptops typically use smaller memory modules to save space. The types of memory found in laptops include:

Some laptops offer upgradeable memory with removable panels that allow easy access to the memory modules for upgrades.

­

Similar to a desktop, a laptop also contains an internal hard disk drive that holds the operating system, applications, and data files. However, laptop hard drives tend to have less storage capacity than those in desktops. Additionally, laptop hard drives are physically smaller and usually rotate at slower speeds, leading to reduced heat generation and lower power consumption.

Desktop computers are equipped with multiple bays for adding extra drives, such as CD and DVD ROM drives. In contrast, space is much more limited in laptops. Many laptops utilize a modular design that allows various drives to fit within the same bay. These drives are categorized into three types:

In some instances, these drive bays can also accommodate extra batteries in addition to storage drives.

Next, let's explore the video processing and display capabilities of laptops.

Laptop Screen, Graphics, and Sound

A graphics processing unit (GPU) is a microprocessor responsible for the complex calculations involved in rendering 3-D graphics. Like a CPU, the GPU generates substantial heat. In most laptops, graphics capabilities are either integrated into the motherboard or handled by smaller graphics cards designed specifically for laptops. Leading GPU manufacturers ATI and nVidia produce models tailored for laptop use. Additionally, laptops often share memory between the CPU and GPU, helping save space and minimize power consumption.

For many users, a laptop's graphic performance is more than sufficient. While they are powerful enough for everyday tasks like web browsing and productivity apps, they may not perform as well with the latest 3-D games. However, certain high-end gaming laptops come equipped with more robust GPUs and additional video memory to meet these demanding requirements.

Laptops showcase their graphics on a liquid crystal display (LCD) screen. These screens typically range from 12 to 17 inches in size, and the screen size influences the overall size of the laptop. Additionally, laptop screens can feature the following characteristics:

Active matrix displays offer crisper images and are easier to read, while backlit screens excel in low-light environments.

Most laptops come equipped with sound cards or integrated sound processing on the motherboard, along with compact built-in speakers. However, the limited internal space of laptops typically doesn't allow for high-end sound cards or premium speakers. Enthusiasts of gaming and high-quality audio can enhance their laptops' sound systems with external sound controllers, which connect via USB or FireWire ports.

Laptop Batteries

Laptops, like desktops, rely on electricity. Both use small batteries to power the real-time clock and, in some cases, CMOS RAM. However, unlike a desktop, a laptop's portability allows it to run on battery power alone.

Nickel-Cadmium (NiCad) batteries were the first widely used type in laptops, and older devices may still use them. They offer around two hours of use between charges, but this duration decreases with each charge due to the memory effect. Gas bubbles form within the cell plates, reducing available space for recharging. To avoid this, the battery must be fully discharged before recharging. Another disadvantage of NiCad batteries is their risk of exploding if charged for too long.

Nickel-Metal Hydride (NiMH) batteries served as a transition from NiCad to the newer Lithium-Ion (LiIon) batteries. They offer longer usage between charges than NiCad but have a shorter overall lifespan. While they still experience the memory effect, it is less pronounced than in NiCad batteries.

LiIon batteries are the current standard for laptop computers. These batteries are lightweight, have long lifespans, and do not suffer from the memory effect. They can be charged at any time without the risk of overheating or damage. Furthermore, LiIon batteries are thinner than other types, making them perfect for slim, ultra-thin notebooks. They can endure anywhere from 950 to 1200 charges.

Many laptops with LiIon batteries claim to offer a 5-hour battery life, but this can vary significantly based on usage. Components like the hard drive, other disk drives, and the LCD display consume a large amount of battery power. Even maintaining wireless Internet connectivity requires some energy. To help extend battery life, many laptop models come with power management software that reduces power consumption when the battery is low.

Whitebooks

Many people build custom PCs for themselves or for clients. These DIY computers, known as whiteboxes, constitute a significant portion of the computer market. Some individuals also modify their computers for aesthetic or performance improvements. This process is referred to as modding. But what about building or modifying a laptop?­

A modified or custom-built laptop is called a whitebook. Whitebooks currently make up about 5 percent of the laptop market, and this percentage is slowly increasing. The industry has largely succeeded in keeping consumers from modifying laptops. They've made it difficult to open, upgrade, or replace parts in a laptop. Additionally, opening the laptop chassis typically voids the manufacturer's warranty.

Building a laptop from scratch is still challenging due to the limited availability of parts, but companies like ASUS and ECS provide options for customers to purchase blank laptop shells. These are particularly popular with resellers who assemble whitebooks and sell them to end users. Additionally, buyers can modify or upgrade components within the shell. Businesses like TechStyle have turned this into a lucrative venture.

A laptop shell typically includes the following components:

This means that anyone looking to build a whitebook will need to find the following parts:

Currently, there is no universal standard for the form factor (shape and design) of laptop components. While processors intended for laptops are available, sourcing a compatible motherboard for those chips can be challenging. Hard drives follow standard specifications, and SODIMM system memory is widely accessible, but other components may require more effort to locate.

Next, let's dive into the history of laptop computers.

Laptop History

In the 1970s, Alan Kay from Xerox's Palo Alto Research Center envisioned a wireless, portable computer about the size of a notebook. He named it the Dynabook. Though Kay's Dynabook remained confined to sketches and a cardboard prototype, it sparked the idea for what would eventually become the modern portable computer.

In 1979, William Moggridge from Grid Systems Corporation introduced the first fully operational portable computer: The Grid Compass Computer 1109. It featured 340 kilobytes of bubble memory, a die-cast magnesium body, and a folding electroluminescent display screen. NASA purchased a few units at $800 each for their space missions.

In the years that followed, other companies like Gavilan Computer and Apple brought out their own portable computers. However, the first commercially successful model was the IBM PC Convertible, which was introduced in 1986. The PC Convertible had the following specifications:

Weighing 12 lbs (5.4 kg), the PC Convertible retailed for $3,500. It was the first portable computer to adopt the clamshell design that is now standard in modern laptops. The success of the PC Convertible inspired competitors like Compaq and Toshiba to switch to the clamshell design, marking the dawn of the laptop era.

For more details on laptops and related topics, be sure to check out the links provided on the following page.