Buying guidance for Computers

Computers come in many forms and all have different performances. Which would suit you best?
Below is a short overview of the advantages and disadvantages of the various computer types that are available.


Desktop computers

Advantages Disadvantages Options

Desktop computers deliver more computing performance for their price than laptops.

Many styles and configurations to cater to different tastes and performances.

In general desktop computers can be upgraded with more or better internal components in the long run.

More easy or cheaper to repair.

You can choose to have larger screens and well-sized keyboards, which is ergonomically beneficial and makes a desktop better suited for productivity tasks.

Desktop computers and their peripherals, such as keyboard, mouse and speakers, take up more space than laptops.

Not all models have speakers, a webcam or microphone. These can be bought separately.

Integrated desktops, or All-in-one computers: A computer with an integrated monitor. Most look like a computer monitor on a stand, with the computer components built-in in the back of the monitor, and usually include speakers and webcam. Some also have touch screens. All-in-ones are more expensive, and can be difficult to repair. They do take up less space than regular desktop computers.

Mid-size, full-size towers: Regular desktop computers come in various casings, of which mid-size towers are the most frequent. Full-size towers offer the most space for internal additional hardware expansions.

Gaming desktop computers: These computers offer high performance by using the fastest processors and videocards, ample RAM and fast hard drives. They usually come in large casings with lots of room for expansions. As they are meant to be used with graphically very demanding videogames, they can consume more power than an average desktop computer.


Notebook computers

Advantages Disadvantages Options

Notebook computers are portable and can run on their battery.

Notebooks are smaller than desktop computers and can fit in a bag.

They are relatively feature-complete with speakers and webcam.

Notebook computers are expensive for their computing power compared to desktop computers.

They are difficult to repair because many components are tightly integrated.

Large notebooks (17 inch or larger display): Larger notebooks are meant as desktop replacement for entertainment or work. For these tasks they are more powerful with faster processors and dedicated videocards. This makes them consume more energy, so they have a short battery-life compared with smaller notebooks.

Ultrabooks: Top-of-the-line premium notebooks with a display of 13-15 inches. They are the thinnest, lightest and most energy efficient notebooks available, and utilise only fast SSD hard drives for storage.

Convertibles: These notebooks can be 'converted' by folding the keyboard part to the back of the display, so they can be used like a tablet. Their displays are touch-sensitive.

Two-in-one notebooks: These notebooks let you detach the display from the keyboard, so the display part can be used like a tablet. Their displays are touch-sensitive.

Chromebooks: These are cheap and small notebooks that run on Google's Chrome operating system. They are intended for light activities, such as writing, emailing and web browsing. As they have very limited storage, they are best used with online cloud storage services, such as Onedrive, Dropbox or Google Drive.


Tablets or slates

Advantages Disadvantages Options

Small, thin and lightweight.

Long battery life.

Easy controls by using touch displays.

Tablets are very feature-complete with speakers, gps and front and rear cameras.

Ergonomically not well suited for office productivity tasks. When typing is important, an additional wireless keyboards should be considered.

Regular tablets: Ideal for casual viewing of photos or videos, light gaming, and occasional emailing and web browsing.

High-end tablets: These more expensive tablets are more powerful, and are targeted towards productivity tasks. They are presented with accessories such as attachable keyboards and pens.


Energy consumption

As the tables above show, different computer types have different energy uses. This is also affected by the time a computer is actually in use, in sleep or switched off. You can compare many usage scenarios with the various computer types with our Energy Calculator, and see the possible effects on your energy bill.

Click here for the Energy Calculator.


Computer components

The functionality and performance of a computer can be described by its advertised components. Understanding what these component mean can help you make a better choice for your needs. Here is a description of some components that matter most in a computer's practical performance.

CPU, Processor

The CPU (central processing unit) is the brain of the computer. The CPU is the most important component for your computer's overall performance. The speed of the CPU is determined by its number of cores and its clock speed.

The number of cores is often described in words like dualcore (2 cores), quadcore (4 cores), hexacore (6 cores) and octacore (8 cores). The more cores, the more data the CPU can process simultaneously. Clock speed is measured in GHz (gigaherz). The higher this speed, the faster a core can process data. So in general this means, the higher the numbers, the faster the computer.

For most office tasks, music listening, video viewing, web browsing and emailing a dualcore CPU is usually powerful enough. Four cores or higher would be advisable when more multitasking, graphics- or calculation intensive work is being done.

RAM, Memory, System Memory

RAM (random access memory) is the computer's working memory to store actively used data while the computer is switched on. Memory is measured in GB (gigabytes). The higher this number, the more data the computer can hold while working, which can make the computer faster up to a point. For desktops and notebooks you should look for at least 4 GB RAM; for tablets go for at least 1 GB of RAM.

Video Card, Graphics Card, Graphics Adapter

The video card renders the graphics or images on your display. A video card or graphics adapter is a separate card in the computer and has a 'discrete' graphics processor with its own dedicated graphics memory. Video cards are intended to deliver more or the highest graphics performance for a computer. To be able to do that they need their own cooling, usually having one or more fans on the video card.

A video card is especially useful for graphically demanding games. The faster the card, the more fluid the graphics can move and the more detail can be shown.

Video Memory, Graphics Memory

The memory on a video card that is exclusively used by the discrete graphics processor to store data for graphics calculations while the computer is switched on. With todays top-tier games, gamers should get at least 1 GB of video memory on their video cards. Generally speaking, the more video memory, the more detailed surfaces the objects in games have.

Integrated Graphics Processor

Many motherboards nowadays have an integrated graphics processor (IGP) to provide graphics for the computer display. An IGP is usually slower than a dedicated video card, because of its limited size and because it cannot be cooled by a dedicated fan. AMD have integrated a graphics processor into their CPU package, calling it an APU ("accelerated processing unit"). These APUs in general have a higher graphics performance than IGPs.

The IGP uses the computer system's RAM for its graphics memory, so it is advisable to choose a larger amount of RAM when you do not intend to have a dedicated video card in the computer.

Hard Drive, Hard Disk, SSD, Hybrid Drive

This is a device in your computer to store the operating system, programs and your own files (e.g. photos, music, etc.). Its origin was a hard disk, because it was made of magnetic discs to store data. Today there are two types of hard drives: the conventional hard disks and the solid state disks (SSD).  The storage capacity is measured in GB (gigabyte) or TB (terabyte = 1000 gigabytes).

Hard disks have rotating discs, and their speed is defined in rpm (revolutions per minute). The usual spinning speeds are 5400 and 7200 rpm. Hard disks are relatively cheap and can offer large storage capacities beyond 4 TB.

An Solid State Disk (SSD) are called solid state, because they have no moving parts and utilise memory chips to store data. This makes them many times faster than regular hard disks. SSDs use significantly less energy than hard disks, resulting in a longer battery life of notebooks. As a newer technology, SSDs are (still) rather expensive, and therefore the 120 - 250 GB SSDs are the most commonly sold storage capacities at the moment.

A hybrid drive is a combination of a hard disk and a small SSD. It combines a hard disk with large cheap storage with the speed of a SSD. The device determines the placement of data in SSD or hard disk entirely by itself, optimised to your usage pattern. It will store your most frequently used files and programs on the SSD, and the rest on the hard disk.

The faster the hard drive, the faster the computer can start up, and load programs and files from the hard drive.

Memory Card Slot, SD Card Slot

A slot to insert a memory card for reading or writing data on memory cards, which are often used in photo cameras and smartphones. Tablets typically have a slot for expanding their storage capacity. The capacity is measured in GB (gigabyte). An SD card is a widely used memory card format, and comes in several physical sizes. There are adapters for different sized SD cards.

If you use memory cards in other electronic devices, it would be useful to have a memory card slot in your computer as well for a quick transfer of files.

Optical Drive

Optical drives are for reading -and often also recording on- optical discs. With an optical drive you can listen to your CDs or watch movies on DVD or Blu-ray. Software can also be delivered on a CD-ROM or DVD disc for installation.

Most optical drives can write ("burn") (re)writable optical discs, so you can record your data on these discs. Be aware that these burned optical discs should be kept out of sunlight for a longer retention of the data recorded on them. Typically the data on recorded optical discs can fade away after 5-8 years.


Computers have various ports for different functions. There are ports for connecting to various peripheral devices, such as a mouse, keyboard, printer, webcam, etc. The most widely used ports for peripherals are USB ports. Tablets use a micro USB port for data communication, but also for power charging. Other available data port types are e.g. FireWire for connecting with digital camcorders, eSATA for external hard drives, etc..

Ethernet ports connect the computer to your network or internet. With the ubiquity of wireless networks (WiFi), an Ethernet connection often is not necessary anymore. However, these physical ports generally provide faster and more stable connections.

For connecting to monitors, the most used port types are VGA, HDMI, DisplayPort and DVI. Some computers (especially notebooks for business use) use USB 3.0 for an external monitor.

Finally there are audio ports to connect a headset, microphone, loudspeakers or audio receiver/amplifier.

Touch Screen

A touch screen is a display screen that is sensitive to touch, well known from smartphones and tablets. Some notebooks and all-in-one computers also have touch sensitive screens.

Fingerprint Scanner

As an alternative to using passwords, fingerprint scanners are more convenient for logging on to a computer. Fingerprints and other personal biological information of a user are called biometrics. Other available biometric scanners to identify the user are cameras for face recognition or iris scanning. Biometric scanners are available on notebooks as an integrated device, but are also becoming available on regular computers as well (either integrated or as a peripheral device).


The above information is based on the buying guidance of the USA EPA ENERGY STAR website.

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