Requirements for Dual Graphics Cards
To use dual graphics cards, your computer needs AMD or Nvidia technology that links the cards to produce a single output. The AMD graphics technology is CrossFire and the Nvidia technology is SLI. For each of these solutions, the computer must have a compatible motherboard and the motherboard must have the necessary PCI Express graphics slots. Dual graphics cards also require a desktop case that is large enough to fit the extra hardware and a power supply that can run dual cards. The cards must be linked using a bridge connector; which may be included with either the GPU or the motherboard. Finally, the SLI or Crossfire feature must be enabled in the GPU driver control panel.
Benefits
The primary benefit of running two graphics cards is increased video game performance. When two or more cards render the same 3D images, PC games run at higher frame rates and at higher resolutions with additional filters. This extra capacity improves the quality of the graphics in games. Most graphics cards render games up to 1080p resolution. With two graphics cards, games run at higher resolutions, such as on 4K displays that offer four times the resolution. In addition, several graphics cards can drive additional monitors. A benefit of using an SLI or Crossfire-compatible motherboard is that a PC can be upgraded at a later time without replacing the graphics card. Add a second graphics card later to boost performance without removing the existing graphics card. Manufacturers upgrade graphics cards about every 18 months and a compatible card may be difficult to find after two years.
Disadvantages
The primary disadvantage of running dual graphics cards is the cost. Top-of-the-line cards can cost $500 or more. While both ATI and Nvidia offer lower-priced cards with dual capability, you can spend the same amount of money for a single card with equal or better performance than two low-priced GPUs. Another disadvantage is that not all games benefit from multiple graphics cards and some graphics engines do not handle two cards well. Some games may show a decrease in performance over a single graphics card setup. In some cases, stuttering makes the video game look choppy. Graphics cards are power-hungry. Two graphics cards installed in a computer can double the amount of power required to run them in tandem. For example, a single high-end graphics card might require a 500-watt power supply to function properly; two of these cards may require 850 watts. Most consumer desktops aren’t equipped with high-wattage power supplies. Refer to the computer power supply wattage and requirements to determine if your system can run dual graphics cards. The performance benefits of a dual-card environment vary depending on the other components in the computer system. Even with two of the highest level graphics cards, a low-end processor can throttle the amount of data the system provides to the graphics cards. Dual graphics cards are typically recommended only in high-end systems.
Who Should Run Dual Graphics Cards?
If you don’t play video games or use two monitors with your computer, you won’t see an improvement in system performance by running dual graphics cards. The cost of the motherboard, the cards, and the other core hardware can be expensive. However, if you run games across several displays or at extreme resolutions, dual graphics cards will improve your game speed and enjoyment.
