Sunday, November 27, 2005

Anatomy of a Laptop Computer

You may not know your Centrino from your Bluetooth, but understanding these terms are crucial in helping you decide which laptop is right for you and how much to pay.

Here’s an overview of the important features that make up a laptop computer. If a listing doesn’t provide this information, click “Ask seller a question” to find out more.


A laptop’s processor, or Central Processing Unit (CPU), is its brain. The faster the processor, the better your laptop will perform. However there are a number of things to consider when looking at laptop processor speed:

Centrino: If you’re a regular Internet user who likes to be on the move, look out for “Centrino” in a laptop item listing. Centrino is Intel's mobile processor technology that allows you to use wireless networking, and it comes as standard on many new high-end laptops.

Performance vs battery: With a laptop, there’s a trade-off between performance and battery life. AMD and Intel make several processors typically found in laptops. Some optimise laptop battery life while others concentrate on performance. Mobile processors, with the word “mobile” or just the letter M in their names, are a good choice – for example Mobile Intel Pentium 4 or Athlon XP Mobile. These use less power and generate less heat than processors designed for desktops.

Unless you need a powerful desktop replacement, get a mobile processor to extend battery life and prevent overheating. Most users should start with a 2GHz Pentium 4-M, 1.7GHz Celeron-M or 2200+ Athlon XP Mobile and work their way up. Laptops featuring Intel’s wireless processor technology Centrino, such as the Dell Latitude, Sony Vaio X505, Toshiba Tecra A2, Acer Aspire, Dell D505 and IBM ThinkPad R40, provide the best balance of battery power and processor speed.

MHz and GHz: Processor speed (also called CPU frequency) is measured in MHz and GHz (gigahertz and megahertz; 1GHz equals 1,000 MHz). Processor speeds of 1.4GHz to 1.6GHz are fast enough for most laptop users. Popular laptops with processors around this speed include the Sony Vaio and Dell Latitude D600. However you will find many high-end “desktop replacement” laptops on eBay with processor speeds of 3GHz or more. Examples include the Fujitsu-Siemens LifeBook N6010, Dell Inspiron 6000 and HP Pavilion zd range.

Popular laptop processors:


Pentium-M: Battery-efficient but relatively fast, with speeds up to 2.1GHz. Part of Intel's Centrino technology with built-in wireless (Wi-Fi). Found in laptops including the IBM ThinkPad, Toshiba Qosmio and Dell Inspiron.

Celeron-M: Budget predecessor to Pentium-M, with speeds up to 1.5GHz and low battery usage. Ideal if you just want your laptop for email, internet access and word processing. Found in laptops including the Fujitsu-Siemens V2010 and Compaq Presario.

Celeron: Intel’s lowest-price processor with speeds up to 2.5GHz. More battery-draining than Celeron-M. Found in popular affordable laptops including Dell Latitude and Toshiba Satellite.

Pentium 4: Designed for desktops but good for laptop owners who love multimedia. Speeds up to 3.33GHz mean they get hot and drain the battery. Best for desktop replacements that you intend to leave plugged in. Found in laptops including the HP Pavilion zd series, Samsung P10, Acer Aspire and Sony Vaio.

Mobile AMD Athlon 64: Comparable to Pentium-M: fast, wireless-compatible and good for battery life. Found in Compaq Presario and Acer Ferrari series.

AMD Athlon 64: Fast and popular among computer gamers; usually found in desktop replacements. Drains the battery. Also found in Compaq Presario and Acer Ferrari series.

Note: On eBay you’ll find similar laptops containing different processors. For example the hugely popular Dell Latitude and Sony Vaio laptops are available on eBay with Pentium-M, Celeron-M or Pentium 4 processors. Make sure you know the processor type and speed before you bid.

Hard Drive

Your computer’s operating system and all your files and documents are stored on the hard drive (also known as hard disk). You only need a 20GB to 40GB hard drive for basic word processing and a few digital photos, but for high-resolution images, video or your entire music collection you’ll need at least 80GB. Some laptops can work with hard drives up to 100GB and even 120GB; examples include the Dell Latitude, Toshiba Qosmio and Acer Aspire.

Most laptops on eBay have hard drives made by a handful of large companies including Samsung and IBM, though Fujitsu-Siemens make specialist laptop drives.

You can access your laptop’s hard drive and transfer data to and from it via various types of port (“bus”), including USB and the faster FireWire/IEEE 1394. You can use these ports to expand your hard drive capacity with an external hard drive.

Hard drives are now found in all sorts of gadgets as well as laptops. They’re in MP3 players, PDAs, digital cameras and personal video recorders (PVRs, like Sky+). Samsung and Nokia produced the first hard drive mobile phones.

RAM Memory

Random Access Memory (RAM) is your computer’s short-term memory. The more RAM a desktop has, the more efficiently it runs. For example Windows XP requires at least 128MB RAM to run, though you’ll probably need 256MB. Most laptops come with a standard 256MB of RAM, but 512MB is better if you plan to use your laptop for digital video or downloading music. Check the laptop’s RAM capacity to see how much room you have for upgrades.

If you’re on a budget or just looking for a laptop word processor, models in the Toshiba Satellite and Compaq Armada series come with less than 64MB or RAM but are very budget-friendly. At the other end of the scale, gamers and video editors should invest in a laptop with 2GB RAM or more, such as a Dell Inspiron or Fujitsu-Siemens LifeBook.

Screen Size

Most laptops have LCD (liquid crystal display) screens that come in a range of sizes from 12- 17-inches, measured diagonally. The most common size is 15-inches, but if you’re planning to work on your laptop a lot or use it for video editing or gaming, look for a bigger screen size with a decent resolution of around 1024/768 pixels.

You may see the acronym TFT in a laptop listing along with screen size. This stands for “thin film transistor” (also called active matrix) and means the screen is designed to perform better in bright light and can produce clearer images – handy if you fancy working next to the window. TFT LCD screens, found on high-end laptops such as the Dell Inspiron 9300, give excellent displays for more money than standard screens.


Portability may be an important factor in choosing a laptop, but remember that lighter and smaller laptops tend to be less powerful. However, it can depend on what you pay. The most expensive laptops are small and light-weight but relatively powerful; the cheapest laptops are relatively heavy but not very powerful.

The cheapest laptops you’ll see on eBay weigh around 3kg (more than 6lb) – not ideal for carrying around, especially when you’ve added the weight of a case, spare battery, cables and external drives.

Not all heavy laptops are budget choices. Some desktop replacement laptops, such as Dell Inspiron 9200, Toshiba Qosmio G20-108, Toshiba Satellite P20-801 and Sony Vaio B100, have all the features you’d want from a full-sized desktop PC, and they tend to cost more than equivalent desktops. However they are too heavy for most people to carry around for very long. Fine for occasional trips, but not for very regular travellers.

Laptops described as “ultraportable” or “thin-and-light”, such as the light-weight Sony Vaio VGN-U750P, Averatec 4265, Apple PowerBook G4 and Toshiba’s Portege series, can be very powerful (and expensive) but are much easier to carry for long periods.

Connection Ports

Ports allow you to connect external devices to your laptop – for example a large monitor, printer, scanner, digital camera or MP3 player. Many people who work on desktop replacements connect a standard keyboard and mouse to the laptop, because laptop keyboards can often be too small for comfort, and touch-sensitive mouse-substitute pads can be tricky to use.

Most new laptops have one or more high-speed USB 2.0 or Firewire/IEEE 1394 ports, but ensure that your laptop has enough ports of the right type for the devices you intend to plug in.

Drives and Burners

On old laptops you may only find a floppy disk drive – if that. Most recent laptops have more sophisticated fixed internal CD and DVD drives and burners that let you transfer huge amounts of data to and from CD-ROMs and DVDs. Here are some of the drives and burners you’ll find mentioned in laptop listing:


CD-ROM (read-only memory): Standard on most laptops, and is fine for installing software from CD or playing music CDs.

CD-RW (re-writeable): Read and also record data to CDs. Good if you want to “rip” songs from music CDs and create your own music compilation CDs.


DVD-ROM: This DVD drive reads DVDs as well as CDs, so you can watch movies on your laptop.

Combination drive: The most sophisticated DVD drive is the DVD+RW/+R with CD-RW, which lets you write data to DVDs as well.Very handy if you want to save lots of data on a DVD, which has seven times the capacity of a CD

Hot swap bay: These bays let you insert and remove a CD drive, DVD drive or combination drive. With hot-swap bays you can always upgrade to a different drive later, and you can sometimes use them to attach an extra battery.

Laptop Upgrades

Upgrading means replacing an older system with more recent hardware or software to bring the computer up to date. A laptop’s size makes it more difficult to upgrade than a desktop, but it’s easy once you know how, and you will find all the necessary hardware and software on eBay:


Extra RAM: You may want to buy a 1GB RAM stick to increase your computer’s memory. To run Windows XP Home, Microsoft recommends you have 128MB RAM, but it performs much better with 512MB RAM.

New hot swap drive: Make sure your laptop is suitable – check with the seller.

New Ethernet card: Some laptops have an Ethernet or modem card in the PCI or PCMCIA slot (inside the computer), but if you have an open card slot you can quickly add USB 2.0, Firewire, an Ethernet port or wireless (Wi-Fi).

When upgrading hardware such as RAM, make sure your laptop can be upgraded and that the hardware is compatible. Before you bid, check that the seller can include the laptop’s instruction manual.

Tip: We’ve put together a Computers & Networking Buying Guide Glossary to help you understand the terms that appear in eBay listings.

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