PC Builder Buyer's Guide: Choosing a Graphics Card
The Purpose of This Guide
The purpose of this article is not to rate specific graphics cards. The goal of this article is to explain various considerations a buyer should keep in mind when shopping for a new graphics card. New graphics cards come out every few months and that changes everything. The purpose of this article is to explain the different things you should look for when making your graphics card selection.
What is a Graphics Card?
In modern PCs, high end graphical programs offload the heavy duty graphics processing away from the CPU and onto a specialized graphics card. The graphics card generally has one or more processors specifically designed for graphic intensive algorithms and mathematics. These processors, or GPUs, are better at this task than your computer’s CPU, since the CPU has to be good at all sorts of processing tasks. Also, your CPU can handle other tasks more rapidly when the graphics load is shifted to the graphics card. You may have heard a graphics card referred to as a video card. They are essentially the same thing.
There Are So Many To Choose From? Help!
Unfortunately, it seems like GPU makers deliberately try to overwhelm you with choices. Adding to the complication is the fact that while there are only 2 major GPU creators, there are a lot of different companies that assemble the GPUs onto a final market “card” that you install in your computer. The numbering systems tend to be extremely confusing and higher numbers are not always best. Fortunately, both NVIDIA and ATI have taken steps in the last year to simplify the naming of their cards so the numbering is more logical, and so higher numbers are indeed a better card.
NVIDIA vs. ATI
These two companies are the juggernauts of the GPU industry. Unless something revolutionary has happened between the writing of this article and the time you are reading it, those are the only types of cards you will be looking at. As I mentioned, the actual company who assembles the card may be someone else (BFG Tech, EVGA, or someone else), but it will be clear if it is an NVIDIA or ATI card.
On pure speed and power, the current champ changes back and forth depending on which company released their new card most recently. For the most part, they are pretty equal when it comes to power and performance.
What is better about NVIDIA?
NVIDIA has a reputation of better driver support and less conflicts with games and software. They are also the leader in market share, which means gaming and software companies tend to be a little more certain their products work with NVIDIA cards.
What is better about ATI?
ATI cards tend to be a bit cheaper, which is especially useful if you plan to use two cards (see the SLI and Crossfire section below). While they are a little slower to get driver updates out, and conflicts are more common, problems are infrequent. When there is a conflict, usually the software maker or ATI resolves it quickly.
SLI and Crossfire
Briefly, SLI and Crossfire are technologies that allow you to use two graphics cards simultaneously for enhanced gaming performance. In another article I wrote about motherboard selection, I discussed SLI and Crossfire in more detail. Another writer on Bright Hub has an entire article devoted to the question of whether or not SLI and Crossfire are worth it. I highly recommend both articles. My general opinion is that SLI and Crossfire are only worth it if you are a high end gamer or need extreme graphics performance for another purpose. Otherwise, it is not worth the money since many games and software packages do not take advantage of either system. The only time I would personally use SLI or Crossfire is if I wanted to upgrade an older machine a year or two after I bought it, and could buy an identical second card (and at a low price, since it would now be a lot older).
The next section of the article deals with the hardware specifics of making sure the card you pick will actually work with the rest of your computer. Read on!
Interface or Slot Compatibility
Not all graphics cards will work with all computers. The most important thing you need to find out is if the motherboard on your computer has an appropriate interface slot for your graphics card.
At the time of this article’s writing, there are basically 5 different types of interface slots you might have on your computer’s motherboard.
AGP (4x and 8x)
PCI Express (x1)
PCI Express (x16)
PCI Express 2.0 (x16)
The latest graphics cards require PCI Express 2.0 (x16). When shopping for a computer and/or a motherboard, you need to make sure it has at least one interface slot of that type. If you are shopping for a new card for an existing computer, you need to figure out what slots you have and then shop appropriately. There is no wiggle room here. If you don’t have the right slot, you cannot use a card of that type.
Power… We Need More Power!
For the latest and greatest graphics cards, the power supply on your computer might be an issue. The specifications of the card will tell you the minimum power supply needed for one card. If you plan to go SLI or Crossfire, you will need significantly more. ASUS maintains a good power supply calculator on their web site that can help you make sure you have enough power for your graphics card and other computer hardware.
Different graphics cards have different video outputs. If you wish to use your computer as a media center, this could be a serious consideration. The specifications of the card will clearly state what outputs are available.
DirectX and OpenGL Support
DirectX is a set of standardized programming instructions that software vendors can use for graphics and audio in Windows. It is Microsoft’s answer to the OpenGL standard, and most gaming companies make heavy use of DirectX instructions. As a result, DirectX compatibility can be an important issue when choosing your graphics card.
This is usually not an issue, but occasionally when Microsoft comes out with a new version of DirectX this can become a serious consideration. At the time of this article’s writing, DirectX 10 was not supported by all graphics cards on the market. If you wanted to be able to take advantage of DirectX 10, you would need to make sure the card supported it. The same thing could happen with future versions of DirectX. It is generally a good idea to make sure your new card supports the latest version of DirectX.
Choosing the right graphics card can be tricky if you let the number of choices overwhelm you. Ultimately it boils down to a choice between NVIDIA and ATI, a decision on how much you want to spend, and making sure that you choose one compatible with the rest of your hardware (interface slots and power supply). As long as you focus on those things, you will be able to make an informed shopping decision.