How to Install a Dual Graphics Card on Your PC

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Making the Jump to a Dual Graphics Card System

Many PC users know how to install a graphics card, but when it comes to setting up your system in order to utilize a second graphics card, things can get a little trickier. But whether you are setting up a ATI Crossfire system or a Nvidia SLI system, the procedure is pretty much the same.

It’s a fact that SLI and Crossfire are identical in concept, but in practice they do differ from one another. Because of the technologies involved, it isn’t possible to mix-and-match graphics cards from the two, so you can’t pair a ATI graphics card and a Nvidia graphics card together, nor can you run two Nvidia cards on a ATI Crossfire compatible motherboard. So, it’s important to bear a few things in mind when considering making the jump to a dual graphics card system.

Computer Requirement Checklist

CPU-Z will be able to report on your motherboard model and manufacturer. Make a note of the reported chipset and visit the manufacturer’s website to find out whether or not your motherboard can support dual graphics cards. Even though your motherboard may have two PCI Express x16 slots, it doesn’t necessarily follow that you’re system supports either dual card format.

Inspect the internals of your system. Firstly, check that there is sufficient room in your PC to house a second card and ensure that the second PCI Express x16 slot isn’t obstructed by cables or other hardware. Graphics cards can be quite lengthy and those that are fitted with large heatsinks can take up two expansion slots.

Check that your power supply can provide enough juice to power your dual card system. Although some power supply manufacturers have certified their power supplies to be compliant with dual card systems, check the specifications of the power supply in your system. Ideally, the power supply should provide at least 500 watts of power, but it’s wise to check the exact power requirements for your SLI or Crossfire setup. Also check that your power supply has a suitable spare connector should your graphics card require one.

The next step is to check that your existing graphics card supports the same standard as the motherboard. While in a single card setup, you can use a Nvidia graphics card with a Crossfire motherboard and vice-versa, the same cannot be said for using two cards. If you have a Crossfire motherboard, you are restricted to using graphics cards which have ATI graphics processing units; the same is true for SLI-enabled motherboards and Nvidia graphics cards.

SLI and Crossfire configurations are only available on Windows XP and latterly on Windows Vista operating systems .

Update your Drivers

Before starting the upgrade, you should download the latest available drivers for your graphics card. For ATI cards, you will need the full driver version with Catalyst Control Center. If you are running Windows XP, you will also need to download and install Microsoft’s .Net Framework 2.0. Then install the driver and restart your system to complete the driver installation.

Remember, however, that if you are changing graphics cards vendors, you should uninstall the current driver before installing the new driver, otherwise you may experience problems with the installation and performance later.

Installing the Second Graphics Card

Now, with the PC turned off, its time to install your second graphics card into your system. Remember to ground yourself by touching exposed metal on the inside of your PC case or a radiator in order to discharge any build up of static before you touch any of the components.

Locate your free PCI Express x16 slot and the blanking plate that aligns with it. Remove the blanking plate, or plates if your card will require two expansion slots and then remove the graphics card from its packaging. Take care to hold the card only by the edges, otherwise you may damage some of the more delicate areas of the card.

Line the graphics card up with the free slot and insert the card into the slot with a firm push - don’t be scared to use a little force if need be. Make sure the card is fully in the slot, and then secure the card to the backplate of your PC with a screw or clip depending on your case. Once secured, attach the power connector if required.

Link the two cards together using the connector cable. Most SLI cards use a single ribbon cable which resembles a miniature IDE cable, while Crossfire cards have two. Earlier Crossfire configurations used external pass-through cables, but the latest incarnation uses ribbon connectors similar to the SLI bridge. For both formats, the connectors fit onto the cards via the top edge of the cards.

Once the cards are connected, the next step is to activate the dual card setup. Some motherboards require you to do this manually by repositioning a jumper on the motherboard or via an option in the BIOS. Your motherboard manual should tell you how to enable the system for using dual cards. Some SLI motherboards use DIP switches, while on some older motherboards, there would be a small card which would lie flat between the two PCI Express x16 slots. Turning this card around would alternate between Normal and SLI mode. Once you are finished, put the case back on and power up your PC.

Once your computer has booted into Windows you should see a ‘Found New Hardware’ message on your screen. As the driver is already installed, the installation should complete autonomously.

If you are setting up a Crossfire system, once Windows has restarted go into your Catalyst Control Center and select the Advanced Setup option. This provides a list of graphics settings; scroll to the Crossfire option, tick the box to activate and your display should go black momentarily while Crossfire is initialized. Once the display returns, you should see an information box confirming that Crossfire has been activated.

If you are setting up a SLI system, once Windows has restarted, select the Nvidia Control Panel and enter the 3D settings tab. Click on Set SLI Configuration and click the radio button to Enable SLI Technology. Click ‘Yes’ to apply changes and exit the Control Panel. Restart your computer and when it has rebooted fully, you should see a pop-up message confirming that SLI has been enabled.

All that remains now is to enjoy your new graphics power!