Computer buying guide

Also known as the CPU (central processing unit) by Intel and CPU and APU (accelerated processor unit) by AMD, this is the computer's “brain,” responsible for processing information. Performance is the most important factor, and is determined primarily by the number of cores it has and its clock speed.

Intel and AMD are the dominant processor manufacturers. Within each company's product lines are various processor families.

Intel's include the Atom, Celeron, Pentium, and Core; AMD's include the Sempron, Athlon II, Phenom II, E-Series, A-Series, and FX.

Intel's new CPUs are the fifth-generation Core i3, i5, and i7. They're setting a new standard in in battery life, with one laptop we tested lasting a full 19 hours.

AMD's new top processor is called A Series Elite. The A Series Elite integrates discrete graphics into the processor. As a result, you can play more challenging video games on these computers without needing separate graphics processors. They also add an automatic speed boost when needed.

Processors with multiple cores can process more data simultaneously. Check Intel's or AMD's website to determine how many cores a particular processor model has.

Clock speed, measured in gigahertz (GHz), determines how quickly a CPU can process information. Generally, within a processor family, the higher the clock speed, the faster the processor.

Clock speeds typically start at around 1GHz for a mobile processor and can exceed 3GHz for a desktop processor. Processors can up the speed a bit for a brief time to yield maximum performance.

Power consumption is another important factor when choosing a processor, especially for laptops—lower power consumption translates to longer battery life.

When buying a computer, make sure it has a processor that will be fast enough to handle your needs. If you’re looking for a very basic or budget computer to web surf, email, work on Office documents, then the Intel Celeron or Pentium or AMD A4 should suffice.

If you plan to check emails, surf the web, and do some simple gaming, the Intel Core i3 or AMD A6 should do the job.

If you plan to watch videos or play mainstream games, the Intel Core i5 or AMD A8 is a good choice.

And if you're a gamer or plan to edit HD video, go for a high-end processor such as the Intel Core i7 or AMD A10 Series.

The computer's memory, or RAM, is used to store data temporarily while the computer is on. The more memory a computer has, the faster it is, up to a point.

Memory is measured in gigabytes (GB). On desktops, 8GB is common; a few laptops include 8GB of RAM. We've found that for anything other than heavy multitasking or video editing, 4GB is plenty. Many store-bought desktops with the Intel Core i3, i5, and i7 processors have 8GB.

Some computers use face-recognition technology, where the laptop's webcam performs an initial scan of your face and then scans it every time you log on to make sure it matches the initial scan.

We found facial recognition easier to use but less secure than a fingerprint scanner. It didn't work as well in low light and for some faces with glasses. In addition, we found at least one report of the software being fooled by photographs of people's faces.

Windows PCs often cost less than Macs. Windows fans also may choose PCs because they are familiar with them through their workplaces, because they have full compatibility with Windows apps, and because a wide selection of games are available for Windows computers.

Windows 10 continues the work of Windows 8.1, bringing a more uniform interface across a variety of devices: computers, tablets, Xbox, and smartphones. In addition, "universal apps" developed for Windows 10 will look and work the same on a variety of devices.

Macs can be more expensive, but they're less prone to most viruses and spyware, and Apple's support has been tops in the industry in our surveys. The company's phone support is free for only 90 days, but you can get unlimited technical support through the Genius Bar at an Apple Store. Apple's OS X Yosemite is the company's current OS; the new El Capitan version is due to be released this fall.

Also known as the video card, GPU, or graphics card, this hardware is responsible for drawing what you see on your screen. Graphics processing comes in two basic flavors: It can either be integrated into the same chip that's running the rest of the computer, or it can run on a discrete piece of equipment

The vast majority of computers sold have integrated graphics. This has usually been the less expensive and lower-performing option—fine for most computing tasks, but inadequate for gaming. If you wanted a high level of performance, you'd make sure to get a discrete GPU. However, some new CPUs integrate discrete-class graphics. Those include AMD's new "Elite" A Series chips, as well as Intel third- and fourth-generation Core processors that use the HD Graphics 4000 series (and Iris) integrated graphics. They offer excellent graphics abilities without adding a separate chip.

Integrated graphics use up part of your system's memory, so make sure you have at least 4GB of memory in your computer. If you choose a system with discrete graphics, look for at least 256MB of graphics memory. Gamers should get 512MB or more.

If you have an Intel Wireless Display (WiDi)-enabled laptop, which has special Intel hardware and software built in, you can wirelessly stream content to a TV. This includes photos and videos, as well as movies and TV shows streamed from services such as Netflix. It requires you to purchase and connect an external box to your TV.

Similar streaming media technologies include Digital Living Network Alliance (DLNA), Wireless Home Digital Interface (WHDI), and Wireless HD. (Other products, such as Roku and Apple TV, let you wirelessly stream Internet-based video directly to a TV without a computer.)

A few laptops and desktop monitors allow 3D viewing, using either passive or active glasses. We were impressed with the 3D images on those we tested, but it's an expensive add-on, especially when you factor in the cost of the glasses.

If you're buying a desktop, check to see which video outputs it has. Except for all-in-ones, almost all desktops have a VGA (analog) output, but most also have a digital output, either DVI (digital visual interface) or HDMI (high-definition multimedia interface).

VGA is fine for most uses, but for a cleaner, crisper image on large displays, go with DVI or HDMI. You may have to buy a cable, which costs around $10.

If you're buying a laptop, you can use a VGA output with a projector for delivering presentations. Most new desktops and laptops have an HDMI output to feed video to an external HDTV.

Also known as a hard disk, or HD, this is where your programs, documents, music, photos, and videos are stored.

Bigger is better. Hard drive sizes are measured in gigabytes and terabytes, and commonly range from 250GB to more than 1TB (terabyte).

Though size matters, speed is equally important. Speed is measured in rpm (revolutions per minute). A slow hard drive will take longer to start up the OS and programs, and complete tasks (such as installing programs or scanning your hard drive for viruses).

For best performance, get a desktop with at least a 7,200rpm hard drive and a laptop with a 5,400rpm hard drive.

Hard drives often fail after a while, so you must back up your data periodically to avoid losing it. The best option is an external hard drive, which connects to your computer through its USB, FireWire, or eSATA port.

Some high-end desktops and laptops can be configured with a RAID (redundant array of independent disks) setup. These computers have two or more hard drives. There are several types of RAID, the most common being RAID 0 and RAID 1.

RAID 0 distributes your data across multiple hard disks, which can greatly improve speed. But if one fails, you'll lose data on all your drives. RAID 1 automatically copies data from one drive to the other. If one crashes, all your data will be safe on the other.

A service that could ease the agony of a crash is cloud computing. With a backup solution such as Carbonite, all your data resides on the company's servers. Any documents, files, data, applications, and e-mail you put on Carbonite will be available to other computers, as well as iOS, Android, and Blackberry devices.

Solid-state drives (SSDs, also called flash drives) are a newer type of storage technology, letting your computer access data without the moving parts required by a traditional hard drive.

SSDs don't have the spinning disk of a conventional hard drive, so they use less power, work more quietly, and should be more resistant to damage from rugged use. And because there are no moving parts, they promise quicker access to data.

But they cost several times as much as traditional hard drives and have smaller capacities. Lower-priced hybrid drives, which combine a hard drive with solid-state memory, represent a good compromise.

Optical drives let you read and write to CDs, DVDs, and Blu-ray discs.

DVD burners are standard gear on today's desktop computers. They can read and write to CDs and DVDs so you can back up your home-video footage or digital photos, for example. Recordable CDs (CD-R) can hold up to 700MB of data. Recordable DVDs (DVD+R, DVD-R, or DVDRAM) can hold up to 4.7GB (single layer) or 8.5GB (dual layer) of data.

Blu-ray Disc (BD) drives are the newest standard. They're capable of playing Blu-ray movies and can store 25GB (single layer) or 50GB (dual layer) of data, respectively.

Many of today's laptops come without an optical drive, saving weight and cost. With high-capacity flash drives available, extra storage isn't a problem on these models. But installing older software—typically distributed on a CD or DVD—could be a problem. Most of today's software is distributed via download, so there's little need for an optical drive.

Screen sizes (measured diagonally) generally range from 15 to 24 inches, but you can find larger ones. The most common sizes are 19 and 20 inches.

Most are wide-screen, which fit widescreen movies better but give you less screen area per inch. Those who plan to edit photos or videos should note differences in color, viewing angle, contrast, and brightness.

Monitors are often less expensive when bundled with a new computer.

A 15- to 16-inch display should suit most people. Displays that are 13, 14, and 17 inches are also common, and some manufacturers are also offering 11-inch laptops.

The screens on most laptops are glossy instead of matte. Glossy screens have more-saturated colors and deeper blacks but are also much more prone to glare. Like desktop monitors, most laptop displays are wide-screen to fit wide-screen movies better.

LED-backlit displays provide more efficient use of power, resulting in longer battery life. In most cases, color on LED-backlit screens is not significantly different than that on other types of displays.

Borrowing from tablets, companies have begun including touchscreens on many laptops. These have custom, touch-enabled multimedia apps and include multitouch capability, which lets you use your fingers to zoom, turn, and scroll.  

When not plugged into a wall outlet, laptops use a rechargeable lithium-ion battery for power. Laptops go into sleep mode when used intermittently, extending the time between charges. You can lengthen battery life if you dim the display, turn off wireless when it's not needed, and use only basic applications.

Playing a DVD movie uses more battery power than other activities, but most laptops should be able to play one through to the end. Many laptops can accept an extended battery, adding size and weight but giving as much as twice the battery life.

Some laptops, most notably Apples, Ultrabooks, and other thin-and-light models have nonremovable batteries, which may be costly to replace when run-time starts decreasing.

Some all-in-one desktops have a battery. Called “portable desktops,” these models are meant to be moved around a home. They often fold flat to enable multiple users to interact with them simultaneously, such as when playing a game.

Form factors for computers are varied. Mainstream computers usually come in towers, which fit on or under a desk.

All-in-one computers, such as the Apple iMac and HP TouchSmart, pack all the components into the same enclosure as the LCD display, with only the keyboard and mouse separate. Toshiba, Asus, Dell, Acer, Lenovo, and many other manufacturers also offer all-in-one models.

Mini cases include models such as Apple's Mac mini.

For connecting to the Internet, all desktops come with an Ethernet port that lets you run a cable between your desktop and your router. If it's not possible to run such a cable through your home, consider a Wi-Fi adapter. Some desktops have this built in. If not, you can buy one for about $40 and plug it into a USB port. You'll also need a wireless router.

Laptops come with wireless built in, and most have a port for connecting an Ethernet cable.

Wireless adapters mostly use the newer 802.11n standard (which is backward-compatible with 802.11g). The latest use 802.11ac, a new standard.  

Intel's WiDi capability is built into some new laptops that have an Intel Core i-series processor (with a four-digit processor number). WiDi lets you wirelessly stream video from your laptop to a TV. As mentioned earlier, it requires an external box, which costs $60 from Netgear.

WiDi supports 1080p resolution. Similar streaming-media technologies include DLNA, WHDI, and WirelessHD. Other products, such as Roku and Apple TV, let you wirelessly stream video directly to a TV without a computer.

Most of those that come bundled with desktops are optical, meaning light sensors on their undersides track movement.

Apple offers its Magic Mouse, which has a touch-sensitive top surface that works like a multi-touch touchpad.

Some mice are ergonomically contoured to match the shape of your palm, while others are designed to be stylish. They can also be either wired or wireless.

If you have a wireless mouse, you won't have to deal with a cord, but you will have to recharge or replace the batteries every few months.

Most laptops use a touchpad in place of a mouse; you slide your finger across it to move the cursor. You can also program the pad to respond to a "tap" as a "click," or scroll as you sweep your finger along the pad's right edge.

Touchpads come in various sizes; the larger ones let you move the cursor farther across the screen without lifting your finger. Some let you use multifingered gestures for zooming and rotating images.

An alternative pointing system uses a stick the size of a pencil eraser in the middle of the keyboard. If you prefer, you can attach a mouse or trackball.

Most computers come with a standard wired keyboard.

Some keyboards have CD (or DVD) controls that let you pause, play back, change tracks, and change the volume. Some also have additional keys to expedite getting online, starting a search, launching programs, or retrieving e-mail.

Like mice, keyboards can also be wireless.

On most desktops, except for all-in-ones, speakers are optional.

Computers with three-piece speakers include a woofer, which delivers deeper, more powerful bass. If you plan to turn your computer into a home theater or action gaming center, consider creating a six-channel speaker system (commonly called a 5.1 system) adding two rear and a front, center speaker for surround sound. You'll also find connections for audio input and headphones.

The small speakers built into laptops often sound tinny. And a familiar brand name like Altec Lansing doesn't mean they'll sound good. Headphones or external speakers deliver much better sound.

Some larger laptops include better speakers and even a woofer.

The latest port to arrive in computers is USB C. It's reversible, so you'll never insert a USB C plug in the wrong way. It can also be used to supply power to your laptop. With an adapter, it's compatible with earlier versions of USB.

Other ports to look for include USB 2 and 3, FireWire, Ethernet, eSATA, and S-video or HDMI.

USB ports let you connect a variety of add-on devices, such as digital cameras or external hard drives, as well as flash drives for copying files to and from the hard drive. Having these ports at the front of the case makes connecting devices more convenient.

An Ethernet port or wireless network card lets you link several computers in the household to share files, a printer, or a broadband Internet connection.

FireWire or IEEE 1394 ports are used to capture video from digital camcorders and connect to other peripheral devices.

Apple desktops and laptops have a port called Thunderbolt, by far the fastest data-transfer port. However, there are fewer compatible devices available for it than there are for USB, eSATA, or FireWire. Current models include Thunderbolt 2, a faster form of Thunderbolt.

An eSATA port lets you connect an external hard drive for faster file transfer than with USB 2.0. USB 3.0 matches the speed of eSATA-connected hard drives. Some combo ports can serve as either eSATA or USB ports.

An S-video or HDMI output jack lets you run a video cable from the computer to a TV so you can use the computer's DVD drive to view a movie, or stream from an online service such as Netflix to a TV instead of watching on computer monitor.

For laptops: Most laptops have at least two USB ports, with many new models including USB 3.0, for easy hookup of a printer, digital camera, or scanner.

Some new laptops have a USB port that maintains power for charging, say, a smart phone while the laptop is off.

Also common are a wired network (Ethernet) port and an internal wireless-network (Wi-Fi) adapter. Though rare, Firewire ports are still included on some laptops.

Some laptops also have an internal Bluetooth wireless adapter to link to a Bluetooth-capable cell phone, camera, or another laptop.

A laptop's ExpressCard slot lets you add a cellular modem.

Some laptops offer a connection for a docking station, a $100 to $200 base with connections for a monitor, keyboard, mouse, printer, network, and power.

By fitting your laptop into this base you can connect to all these devices at once.

Acer Aspire laptops and desktops run the gamut of computers from budget to high end, including a full line of ultrabooks and detachables.  Acer also produces Chromebooks that run Google's Chrome operating system. Gateway is also owned by Acer. The company does not sell its products direct to consumers, unlike most other computer makers. 

Apple computers usually cost more than similarly configured Windows-based systems. Apple computers use Mac OS X as their operating system, which had fewer problems with viruses and other malware. Macs can also run Windows in a virtual setting. The company offers several consumer lines, the MacBook Pro and MacBook Air (laptops), the iMac (all-in-one desktops), and the Mac mini (a small, budget desktop). The Mac Pro desktop is its professional line. Apple's free telephone tech support is limited to three months, but you can get unlimited free support at the Genius Bar in Apple stores.

Asus offers computers geared toward entertainment, gaming, and everyday computing. It also offers ultrabooks, convertibles, Chromebooks, and all-in-one desktops. Asus does not sell its products directly to consumers, unlike many other computer makers.

Inspiron is Dell's mass-market line of laptops, desktops, and all-in-ones. For higher performance and gaming systems, Dell offers the XPS convertible line. For hard-core gamers, Dell offers Alienware systems. Inspiron One and XPS are its all-in-one brands, and they include touchscreens in some models. There's also a Chromebook geared toward students.

Google, the designer of the Chrome Operating System, offers just one Chromebook, the Pixel.

HP is the No. 1 seller of desktops and laptops in the United States. For laptop users, it offers the mainstream Pavillion line, which includes the G, NE, NV, the Envy high performance models, and convertible and detachable models in the Split and Slatebook line. Desktop lines include the Pavillion and Envy models, and all-in-one Pavillion and Touchsmart lines.  HP also offers a line of Chromebooks.

IdeaPad is Lenovo's consumer laptop line that encompasses mainstream and premium models. Yoga is the convertible series. Lenovo also offers gaming, budget, thin and light, detachable convertibles and Chromebooks. Lenovo ThinkPads are its business notebooks; ThinkCentre are business desktops. IdeaCentre is Lenovo's brand of midrange consumer desktops and all-in-ones. The company also offers Android-based all-in-ones. Erazer is its gaming line.

Microsoft offers the Surface PC, a series of detachable computers.

Samsung offers a variety of laptops ranging from slim and light to detachable to desktop replacements. The line is known as the ATIV Books—with a numbered series. Its all-in-ones are the ATIV One series. Samsung also produces a Chromebook, which runs Google's Chrome operating system. It does not sell its products directly to consumers, unlike many other computer makers.

Sony exited the laptop and desktop market in 2014. The company has promised to continue product support for seven years.

Toshiba's laptop lines include its consumer Satellite line and premium Kira line. The Qosmio line is for high-end gaming. Tecra and Portege are its business laptop lines. The company also offers a Chomebook, which runs on Google's Chrome operating system.

Shop online

Our subscriber surveys have generally found online retailers superior to walk-in stores for selection and price.

You can save money by using coupons and forum sites such as Techbargains, FatWallet.com, and Ebates, which provide information on rebates.

Buy a la carte

If you have special requirements, order from a manufacturer's website. Menus show you all the options and let you see how a change affects the overall price.

Configure-to-order will often give you choices you won't get if you buy an off-the-shelf model. But be sure to double-check your choices before ordering, and look for unwanted items that some manufacturers include by default.

Shop at the right time

January, July, and October are usually good times to shop; new models show up in stores at those times, meaning older inventory must be cleared out to make room. If a computer you like isn't on sale, ask for a better price.

Apple often offers free iPods and educational discounts to students buying computers during the back-to-school season.

Macs aren't discounted that often, so take advantage of the price cuts that usually occur around the time Apple announces new models. That's when retailers such as Amazon.com, MacConnection, and MacMall tend to clear out older stock.

Models from other PC brands may also be discounted when their successors arrive.

Pay attention to ergonomics

Especially when you're buying a laptop, try it before you buy it, if you can.

The keyboard shouldn't bend under continuous tapping, the touchpad should be large enough so that your finger can cover the span of the screen without repeatedly lifting it, and touchpad buttons should be easy to find and press.

Carry the laptop around for a few minutes and make sure it isn't too heavy or too big.

If it's been on for a while, feel the bottom. A laptop shouldn't get uncomfortably hot during use, and it should run quietly.

Glossy screens are now standard on most laptops. Several manufacturers have added antireflective coatings, with mixed results.

Finally, manufacturers are emphasizing design as much as substance; find a laptop that suits your style.

Think green when you buy

Some computers meet the new Energy Star standard for efficient power use. Energy-use guidelines cover three operating modes—standby, sleep, and running—with systems entering sleep mode within 30 minutes of inactivity.

Power supplies also need to operate more efficiently. You probably won't notice much difference in the operation of your computer, but your electricity bill might go down a bit.

Look for the Energy Star label on qualified computers. Prices won't increase because of the new standard, according to a representative for the Energy Star program.

Another standard is EPEAT, which offers guidelines on what materials can be used in a computer. Depending on how well each computer meets the criteria, it is rated bronze, silver, or gold.

A list of EPEAT-compliant systems can be found at www.epeat.net.

Before you toss, try recycling

Most manufacturers have recycling programs that help you to dispose of your old computer, but the programs vary considerably by company. But don't forget to wipe your hard drive before you recycle your old computer.