Laptop Buying Guide: Making Sense of the Specifications Shopping for a laptop, but unsure about the features you need? Here are the most important laptop specs to consider. By Jason Cross, PCWorld Once you figure out which category of laptop best suits your needs, it's time to examine the specifications. You'll have to choose from among a host of options for the processor, RAM, graphics, display, and other features. Deciding what you need and what you can live without is difficult, but it's essential to selecting a laptop you love at a price you can afford. If you don't understand the specs, you could save money but miss out on the features and performance you require, or you could spend too much for things you don't really need. CPU The CPU is the heart of any computer, and is responsible for running the operating system and every application you use. A speedier CPU means faster-running programs, but usually it also means lower battery life and a more expensive laptop. Nearly every laptop has a CPU from AMD or Intel. If you're buying a netbook, you're bound to find that it uses an Intel Atom processor. You won't encounter a particularly noticeable difference in performance between the Atom chips you find on modern systems, but the newer N450 Atom processors do offer slightly better battery life. Ultraportable PCs generally use low-voltage AMD or Intel processors. These chips are usually dual-core CPUs that are quite similar to the regular notebook CPUs found in larger laptops but run at much lower clock speeds (1.2GHz instead of 2.1GHz, for example). Lots of processors--too many to list here--are available in this group, but when you're shopping, you can follow a few general rules: More cache is preferable, and higher clock speeds are better but will drain the battery a little faster. AMD's CPUs are a bit slower than Intel's, but are priced to move. Note, too, that some ultraportables don't use low-voltage CPUs, and are considerably faster (but have shorter battery life) than those that do. All-purpose and desktop-replacement laptops offer both dual-core and quad-core CPUs in a range of speeds. Intel's Core i3 and Core i5 CPUs are excellent for most users; only people who truly need a quad-core CPU (for encoding video, playing games, or running engineering applications, for example) need to look for a quad-core Core i7 processor. Again, more cache and higher clock speeds are better, but any CPU over 2.0GHz is fast enough to handle all the basic stuff, like playing music, surfing the Web and playing Web games, displaying online video, and managing e-mail. You'll still find many laptops on sale with Core 2 Duo CPUs, which are the previous generation of dual-core chips from Intel. These models are perfectly fine for most tasks--just avoid the ones with low clock speeds and small caches (1MB or 2MB), if you can. Be wary of cheap laptops bearing Intel Celeron or Pentium CPUs, or those that carry AMD Sempron CPUs; these processors help laptop manufacturers keep prices low, but they do so at the expense of performance. Graphics The GPU (graphics processing unit) in a computer is useful for more than just playing games. This bit of silicon is ultimately responsible for everything you see on screen, from 3D games to the basic desktop. Perhaps more important for some people, many GPUs can accelerate video decoding: With the latest version of Adobe Flash and the right GPU, Web videos from Hulu or YouTube will run more smoothly and look better (especially if you have a netbook or an ultraportable laptop with a weaker CPU). Most laptops are available with a choice between integrated graphics (from Intel or AMD) or a discrete GPU (from nVidia or ATI, the graphics division of AMD). Integrated graphics are built into either the system chipset (the "traffic cop" that controls the flow of data in the system) or, in newer systems, the CPU itself. They share the main system memory with the CPU. Discrete GPUs are individual chips that are dedicated solely to graphics and have their own pool of memory, which results in far better performance. Integrated GPUs from Intel are generally quite poor: They don't run 3D games well, and their video decoding is lackluster. The GPUs built into the new Core i5 CPUs are much better than previous integrated graphics, but still not as good as ATI or nVidia dedicated graphics. If you want to play games other than the occasional Web-based diversion, you probably want discrete graphics. You'll find lots of graphics chips to choose from, but in general the 5000 series from ATI is faster than the comparable 4000-series models, and the 300 series from nVidia is faster than the comparable 200 series. Within each series, the more expensive models are speedier: ATI's Mobility Radeon HD 5850 is faster than the Mobility Radeon 5650, and nVidia's GeForce 330M is faster than the GeForce 310M, for example. RAM Memory is as important on a laptop as it is on a desktop. In fact, because laptop hard drives tend to be slower than their desktop counterparts, it may be more important--after all, the more RAM your PC has, the less often it needs to load data from the hard drive. It's a good idea to buy at least 4GB of RAM for your laptop, if it's offered as an option. Beyond that, the benefits are usually small, and the cost to add more RAM is very high. Laptop memory comes in two types, DDR2 and DDR3. Of the two, DDR3 is faster and can speed up memory-intensive operations. You'll also see a clock speed listed on some laptop memory specs, like 667MHz, 800MHz, or 1066MHz. The higher the number, the faster the RAM. But spend the money to get to 4GB first, and then worry about speed: If your choice is between 4GB of 800MHz DDR2 memory or 2GB of 1066MHz DDR3 memory, go with the 4GB of slightly slower RAM, as you'll get more performance bang for your buck by doing so. Display The size of the display will be determined in part by the type of laptop you buy: By definition, netbooks have smaller displays than desktop replacements. From there, you have several additional factors to consider: screen resolution, LED backlighting, and a glossy or antiglare surface. Screen resolution is a measure of how many pixels are on the screen, horizontally and vertically. A netbook with a 10-inch screen may offer a resolution of either 1024 by 600 or 1280 by 768, for example; in this case, the screen size is the same, but the latter option will have a lot more pixels crammed into it. This gives you more space on your desktop and lets you see more of the Web pages or spreadsheets you view, for instance. On the other hand, the higher resolution makes all of the icons and text appear smaller, so things can be harder to see. Most users prefer higher resolutions on their displays, but you might want to look at two laptops with the different resolutions you're considering to determine whether you prefer more desktop space or larger icons and text. Many laptops have LED-backlit displays. Instead of compact fluorescent tubes, LEDs (light-emitting diodes) sit behind the LCD panel. LED-backlit displays tend to be more energy-efficient, so the battery lasts longer, and they often provide better contrast. LED-backlit displays are increasingly common, and now can be found in all laptop segments and on most notebook models, at least as an option. You'll also notice that some laptops have a very shiny, glossy display, while others have a soft matte finish on their screen. This is a matter of the coating on top of the display. A glossy coating certainly creates a lot more glare, but it also lets light through more easily; as a result, glossy displays tend to look like they have better contrast and brightness. The matte finish on other displays may result in the appearance of a little less contrast, but it also produces a lot less glare. If you plan to use your laptop outdoors or in brightly lit areas, you might want to consider avoiding a glossy display. Touchscreen displays are starting to appear on some notebooks, from convertible tablet laptops to all-purpose machines and even some netbooks. Finding a portable with a touchscreen is still relatively rare, but it is becoming increasingly common. Expect to spend $100 to $200 extra for this feature. Connectivity Every laptop, from a netbook to a desktop replacement, includes wireless networking. The standard you're most likely to encounter in coffee shops and airports is 802.11g Wi-Fi, and you can't find a laptop these days that doesn't include 802.11b/g support (802.11b is an older, slower networking standard that you don't see much these days). That's the good news. The bad news? Even though the faster, less error-prone 802.11n networking standard is quickly finding its way into homes and Wi-Fi hotspots all over, not all laptops being sold today support this standard. It's a good idea to make sure that your new laptop has 802.11n networking if you want it to be future-proof, or if you want to take advantage of the 802.11n wireless you may already have in your home. Fortunately, 802.11n-capable laptops can still connect to 802.11g Wi-Fi just fine, and 802.11n hotspots almost universally allow 802.11g devices to connect; your connection will simply be slower than it could be. If you need to plug your computer into a wired network, ensure that the laptop you buy has an ethernet jack. Most do, but a few netbooks don't. The standard now is gigabit ethernet, but while some laptops may have slower ethernet jacks (limited to 100 megabits per second), it isn't a major concern. Unless you need gigabit speed to transfer lots of very large files and you're sure you'll be plugging into a gigabit wired network, you don't need to look for that feature specifically. Many laptops also offer Bluetooth connectivity, which is useful for making use of Bluetooth mice, keyboards, and headsets, or for syncing contacts and calendar information with a Bluetooth phone. If you want to connect on the go but no Wi-Fi hotspot is available nearby, you'll need a mobile broadband radio. You can buy one as an add-on card, but many laptops offer built-in mobile broadband radios as an option. Typically these are tied to a single wireless carrier (AT&T, Sprint, or Verizon, for example) and require a mobile data plan to use. If you constantly use your laptop on the road, it can be a convenient option. Some netbooks are available from wireless carriers at subsidized prices along with a wireless data plan, but we don't recommend taking this option--the money you initially save isn't worth being locked into a contract for a couple of years. Optical Drive Most all-purpose and desktop replacement laptops include an optical drive, while most netbooks do not; with ultraportables, it's hit-and-miss. All optical drives in laptops these days will play and burn DVDs. Some laptops even include (or offer the option to add) a drive that can play Blu-ray media and burn DVDs and CDs, which means you can use these models to watch high-def movies. Blu-ray Disc writers--which burn to those high-def discs as well as to DVDs and CDs--remain less common in laptops, and are a more expensive upgrade than the Blu-ray-reader/DVD-and-CD-burner combo. Don't worry too much about the performance ratings on optical drives (expressed, for example, as 8X) unless you plan to do a lot of disc burning. If you have software on CD or DVD that you need to install, or if you want to watch a movie on disc, you can buy an external DVD drive that plugs into the USB port on your laptop. You don't have to buy the drive from the manufacturer of your notebook, and in general the drive will cost between $40 and $60, sometimes less. Look for a drive that's "bus-powered"--this means that the drive can get its power from the laptop's USB bus, and shouldn't need a dedicated power adapter. Storage Hard-drive space on a laptop is just as precious as it is on a desktop PC. Netbooks and ultraportables typically don't offer more than 250GB of storage, while all-purpose and desktop-replacement laptops can have 500GB or more (laptop hard drives are available in capacities up to 1TB, but not all laptops can accommodate the higher-capacity, physically larger 1TB drives sold today). You'll see drives listed as 4200 rpm, 5400 rpm, or 7200 rpm, a measure of how fast the platters spin, in revolutions per minute. Generally speaking, the speedier drives have faster data transfer rates and seek times, which means better file copying, application launching, and boot-up speed. If you plan to store a lot of photos, music, or video on your laptop (or if you intend to install a lot of big games), you'll want as much hard-disk storage capacity as you can get. Some desktop-replacement laptops offer dual-hard-drive configurations. Some laptop models provide an option for using an SSD, or solid-state drive, instead of a standard hard drive. SSDs tend to cost more (adding hundreds of dollars to the cost of the laptop) and offer far less space than the regular rotating magnetic media type, but they're usually faster and far more durable since they have no moving parts. Some SSDs are even more power-efficient than regular hard drives. SSDs can be a good idea for anyone especially concerned with performance or durability, but you'll pay a lot more money for a lot less storage capacity. For more information: To get an idea of which laptop category best suits your needs, be sure to read "Laptop Buying Guide: Selecting the Right Laptop for You." And for buying advice, see our handy "Laptop Buying Guide: Shopping Tips" list.