How to Buy a Video Card

[Lewis]

How to Buy a Video Card
A discrete video card is a must for games, but will boost the performance of other applications as well. You can find one that matches your needs and your budget as long as you keep in mind these few simple things.
Matt Murray By Matthew Murray


Let's face it: Most of the time people buy a video card (also known as a graphics card) for a non-business PC, it's to play games. Oh sure, discrete video cards may offer additional benefits with video playback or transcoding (and, increasingly, Web browsing), but who are we fooling? The main reason discrete video remains such a huge and fiercely competitive market is because, when it comes to playing games that don't come from PopCap or Big Fish, integrated graphics just don't cut it.

The ugly truth about buying a discrete card can be summed up in five sad words: The more expensive, the better. There's almost no way around the fact that the more money you're willing to drop on a video card, the better your gaming experience will be. So if you have $700 (or more—and yes, that is possible) to spend, you're going to be buying yourself an outstanding gaming experience, even if the rest of your computer isn't so special.

That said, there are a few other things you'll want to keep in mind when selecting a video card. They're all subsidiary to that one (sorry), but may help you make a better determination if you don't want to buy a lone card for an amount of money that could buy a complete computer system.

AMD or Nvidia?
Would you believe that this question just doesn't matter that much? I didn't think so. Like "AMD or Intel?", "Windows or Mac?", and "Desktop or laptop?", it's a question that inspires intense—and often nonsensical—debate among each side's adherents. We're not going to lie to you: There are substantial differences in the technologies in AMD's and Nvidia's graphics chipsets, and if you're really picky, you may have a very good reason for choosing one over the other. (We'll touch on this later.)

The truth, however, is that only serious, detail-obsessed gamers are going to be able to discern a difference in appearance between a game running on an AMD card and one running on a comparable Nvidia card. Most people are going to pay more attention to how realistic a game looks and whether it stutters during play, and not the specific type of anti-aliasing, physics processing, and multimonitor technologies that are employed. If you find a card at a price you can afford, and the reviews say it does well, go with it. Most of the other stuff is just gravy—and often lumpy at that. (Note: A few years ago, AMD brought and absorbed video card maker ATI. All AMD's cards now carry AMD branding, but 5000-series and earlier cards may still have ATI emblazoned on them somewhere.)

GPU A video card's graphics processing unit (GPU) is what determines its video capabilities, and many of them have names that are often fairly arcane and unintuitive if you don't follow the business closely. But a good rule of thumb is that the higher the number in the GPU's name, the more recent and more powerful it is. For example, in AMD's current 6000 series, the top-of-the-line (and most expensive) card is the Radeon HD 6990. If you want something just a little more affordable, but still fairly powerful, go for a 6970 or 6950. Or back off a little more still with a 6870. But based on the names alone, you can't necessarily tell how they compare to cards from the previous 5000 series—the last flagship card was the 5970, and one step below that was the 5870. Nvidia, on the other hand, maxes out with the GeForce GTX 590; the GTX 580, GTX 570, GTX 560 Ti, and GTX 550 Ti offer diminishing amounts of performance at lower prices in this generation, but last year the GTS 450 meant something different than the GTX 550 Ti does this time around. Research is important to make sure you know exactly what you're getting that the names might conceal.

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[Lewis]

Clock Speed and Memory
Ultimately, video cards aren't much different from CPUs—a lot of the same rules apply, including the ones about clock speed and memory. Video cards have their own collections of both, though the specific values of either will usually be less immediately important than when you're choosing a system processor. Two video cards of the same type can have different amounts of memory—the GTX 460, one of the price-performance champs from the last generation, is still available for purchase with both 768MB and 1GB—and the one with more memory will tend to be faster (and cost more). Likewise, some cards might use GDDR5 memory, which is faster and more expensive than the DDR3 and GDDR3 memory other cards use. Lower-end video cards often have faster clock speeds to compensate for the power they lack in other areas, but that's usually not going to translate to increased real-world performance. You only really need to pay attention to these specs if you want to fine-tune your purchase; in most cases, the name of the GPU will tell you everything you need to know about the card's capabilities.

Length
Back when all computers were two-foot-tall towers, no one thought much about video cards hogging a lot of space. But because PCs now come in a range of sizes, you may not be able to use every card in every system you want to build. The more powerful a card, the longer it's going to be, and the less likely it will fit into a microATX case, or even a smaller ATX case. At 12.5 inches, the aforementioned Radeon HD 6990 is the longest card you can buy, but other higher-end AMD and Nvidia cards come within an inch of that. If you're building a smaller computer, or you want to upgrade the video in a minitower you already have, be aware that your card choices may be limited.

DirectX
Video cards will support different versions of Microsoft's DirectX collection of advanced programming interfaces (APIs), which offer different graphical and processing features. Again, the specific details are going to be important only to hard-core gamers, but the higher the number of DirectX a card supports, the more realistic games that use it will look—and the more challenging they will be for your computer to run. The current top-level version is DirectX 11 (DX11), and the most recent cards from AMD and Nvidia support it. DX11 cards will also be able to run the full feature sets of games written with DX10 or DX9, but DX9 or DX10 hardware won't be able to see all the effects of DX11 games (assuming they work at all). The software package or the manufacturer's Web site will tell you what version of DirectX is supported—always check to make sure your hardware matches up. All the latest AMD and Nvidia cards support DX11, so if you buy new you shouldn't have a problem.

Output Ports
The most common way to connect your monitor to your video card is with a DVI port, a trapezoid-shaped jack (usually white in color). Just about all current video cards will have one of these, and most will have two, in case you want to hook up more than one display. There are two different types: single-link, which can connect monitors up to 1,920 by 1,080 in resolution, and dual-link which can connect displays as big as 2,560 by 1,600. But there are other jacks out there. You may also find an HDMI port or mini HDMI port, for outputting to an HDTV or other similar device. DisplayPort is an up-and-coming standard that promises support for displays larger than DVI's 2,560 by 1,600; there's also a smaller version of this, with all the same functionality, called Mini DisplayPort. Nvidia has generally standardized its port offerings with two DVI ports and one mini HDMI jack; on its new cards AMD offers two DVI ports (one single-link, one dual-link), one full-size HDMI port, and two Mini DisplayPort jacks. Individual board manufacturers have some leeway in adding or replacing ports, so be sure to check that you're getting what you need for your setup before you buy.

Internal Power Connectors
Video cards are serious business, and if you want the strongest ones on the market, simply plugging them into one of your computer's PCI Express (PCIe) x16 expansion slots isn't enough. Almost all high-performance cards—and increasingly the more powerful midrange cards—require dedicated connections to your system's power supply. These jacks, of which there may be one or two, of either six or eight pins, will be found on the edges of the video card deepest inside the computer (very often near the hard drives). If you don't connect these to the proper cables from your power supply, your computer won't boot. Also, make sure your power supply can handle the card: It's not uncommon for lower-wattage power supplies to not have enough PCIe power cables to drive higher-end video cards. For their more demanding cards, AMD and Nvidia will list the minimum power supply you'll need—take this recommendation seriously!

TDP
For no other component in your computer can the Thermal Design Power (TDP) spec be as important as it can be with video cards. The top-end models really suck up the juice—the dual-GPU AMD Radeon HD 6990 needs 300 watts (and possibly as much as 375 watts if you overclock it), and Nvidia's GeForce GTX 580 about 250 watts. Do some quick math, and if it looks like you'll come close to tapping out your power supply, either choose a different card or buy a new power supply.

Multiple-Card Setups
If your motherboard has more than one PCIe x16 expansion slot, chances are you can add a second, third, or even fourth video card to your computer to really supercharge its video performance (provided your power supply is beefy enough, that is). AMD and Nvidia each have a technology that lets you link up two or more cards, and have the computer recognize them as one powerful video solution. (AMD's is called CrossFireX and Nvidia's is called Scalable Link Interface, usually abbreviated as SLI.) On almost every motherboard on the market, you can't mix and match Nvidia cards—you'll generally want two cards using exactly the same GPU, often even from the same manufacturer. There are a few rare exceptions to this, but that's information that only die-hard gamers and other enthusiasts will really care about.
Special Features
It's with all the little extras that AMD and Nvidia really distinguish themselves from each other. Since 2009, AMD has made a name for itself with its Eyefinity technology, which simplifies setting up and running as many as five or six monitors from a single video card—you can really create your own digital wall, if you want. Nvidia also has a version of this (called Nvidia Surround), but is better known for its use of PhysX, a technology it purchased a few years ago that makes it easier for objects to behave according to real-world physics; and 3D Vision, which lets you play all games in stereoscopic 3D, provided you have the proper hardware (a special 120-Hz monitor and Nvidia's 3D Vision kit). All these technologies don't come for free: Because controlling several monitors, rendering complex animation in 3D, and making glass and fabric look ultra-realistic require a lot more pixels, they can slow even powerful video cards to a crawl. These are fun features, but they're not yet practical for regular use by ordinary users with single-card setups.

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