Best Video Cards

How to choose the best graphics card

Graphics cards represent a significant investment for PC gamers, and are often the single most expensive component in the entire computer system, exceeding even the cost of the Central Processing Unit (CPU).

Further, graphics cards suffer greater technology attrition than most other computer components. Graphics technology increases in speed, stability, and performance on a yearly - and sometimes quarterly - basis. Graphics cards can become outdated in a year or less, and are considered antiquated at three years old, if not sooner.

Insulating against the technology curve and maintaining the best possible dollar value of graphics components isn't easy, and requires addressing several key features and compatibilities of existing cards, as well as industry predictions on future cards and technologies, before a final purchasing decision is made.

Key Features

The most important attributes to consider when purchasing a new graphics card are the three P's: Power, Performance, and Price.

  1. Power is a measure of the raw speed and data-handling attributes of the graphics card. The amount of video memory, the speed in MHz of the Graphics Processing Unit (GPU), and the available bandwidth are all factors that determine power.
  2. Performance is a measure of how well the graphics card will integrate with computer components and software, as well as how long it will continue to perform adequately as new 3D games and software reach the market.
  3. Price might seem obvious, but there is much more involved in properly selecting a graphics card than simply shopping for the cheapest model. A brand new graphics card will certainly be more expensive than an older card, however it will continue to perform for a much longer time.

For now, let's take a look at each of these key features in more detail.

Power

Determining the relative power of a graphics card requires some comparison shopping.

First, analyze the newest model of graphics cards available from major manufacturers, such as Nvidia Corporation and Advanced Micro Devices (AMD). The major factors to consider are:

  1. GPU clock speed in MHz
  2. Amount of video memory
  3. Memory bandwidth
  4. Memory type

For most modern graphics cards: GPU clock speed is measured in MHz or GHz, total video RAM is measured in gigabytes, memory bandwidth is measured in gigabytes per second, and industry standard memory types are updated regularly on a generational basis. Presently, the fastest available video memory is GDDR5.

With these metrics in hand, we can make positive comparisons between the graphics card statistics provided by manufacturers. For example: The fastest graphics card presently available at the time of this writing from Nvidia is the GTX 590. This card offers:

From AMD, we find the newest offering at the time of this writing in the Radeon series, the HD 6990:

While the GTX 590 offers nominal faster memory bandwidth, the Radeon outperforms on all other characteristics, making the Radeon HD 6990 the best possible graphics card presently available.

By comparing the above attributes of other graphics cards available on the market to the HD 6990, we can discern a percentage value for each power characteristic. For example, suppose a competing card offers only 2 gigs of video memory. This is half the amount available on the HD 6990, for a characteristic value of 50%.

Let's also say that our competing card offers a GPU speed of 440 MHz, memory bandwidth of 290, and also offers GDDR5 memory. Rounded down, our final power characteristic values will be:

  1. GPU: 26%
  2. Video memory: 50%
  3. Memory bandwidth: 90%
  4. Memory type: 100%

For a final overall power rating of 66%.

Performance

Now that our power rating is determined, we move on to performance. Key factors in determining performance are:

  1. Compatibility with existing components
  2. Compatibility with existing software
  3. Predicted lifespan before obsolescence

Let's assume that, after a bit of research, we determine that this competing graphics card is fully compatible with our system. This gives a component compatibility rating of 100%.

Let's also assume that our competing card is compatible almost all of our existing software, games, and applications, except for two new games that we want to try. These games will utilize DriectX 11 features that our competing card will not be able to use (see below), however the games will still be playable. Since this is a performance hit on two games we want to try, we mark this rating down by 10%, for a final software compatibility rating of 90%.

However, the competing card is based on an older architecture that is only partially compatible with the newest version of DirectX 11. This means that our competing card has already begun its descent down the technology curve - if it does not fully support DirectX 11, it will most likely support even less of the functionality of DirectX 12, slated for release in 2012.

For this reason, we grant a 33% lifespan rating to our competing card, since it will be obsolete in one year, which is a third of the lifespan of the average graphics card.

Final performance characteristics of our competing graphics card are:

  1. Component compatibility: 100%
  2. Software compatibility: 90%
  3. Lifespan: 33%

For a final Performance rating of 74%.

Price

Once we average our power and performance ratings of 66% and 74%, we come up with a final combined rating of 70%.

Now it's a simple matter of applying this 70% metric to the difference in price between our competing card and the top-of-the-line Radeon HD 6990.

Prices for the Radeon HD 6990 range from $710 - $739 on sites such as Newegg.com and Tigerdirect.com, but let's say we find a special promotion for $699.

$699 x 70% = $489, which means that our competing card must beat this price to be a better value than the new Radeon HD 6990.

Selecting the Best Video Card Summary

Clearly, there are a great many graphics cards available on the market, and making comparisons like this for each one would take a tremendous amount of time. For this reason, it is often best to perform the above process only when we find a graphics card that is discounted, or appears to be a superior value.

In the end, price shopping is still the first step in find a great graphics card value - however, by comparing the power and performance characteristics of any deals we find using the metrics above, we can narrow down our possible purchases and find the best possible graphics card, for the price, that suits our individual needs.