NVIDIA SLI: Assembly and Launch

This section of the review is about assembling a SLI-compatible computer. We will also describe step by step how to make it work correctly. Check up if you’ve got the following, first:

• One SLI-friendly mainboard;
• Two graphics cards on NVIDIA’s SLI-supporting GPUs;
• One sufficiently robust power supply unit.

A comment about the last item in the list: NVIDIA says that the wattage of the power supply be at least 350 watts and  recommends 500 watts and more for a pair of two GeForce 6800 Ultra. We used a 450W PSU from Cooler Master in our tests and had no stability-related problems. Now, let’s get to the assembly.

Suppose we’ve already loaded the CPU and memory slots of the mainboard with appropriate chip and modules and the mainboard itself is already mounted in the system case. We now want to enable the necessary PCI Express mode. In our case, the mode selector was set into the “Dual Card?position by default. This gave us the configuration “PCI Express x8 + x8? And if the selector is set to the other mode, you should just turn it by 180 degrees.

With the A8N-SLI Deluxe, you push on the two locks at the sides of the slot and pull the selector card out. Then turn the selector, insert it back in the slot and press on it until the locks snap in place. The mainboard is ready to take in the graphics cards. Other manufacturers may have other selector devices or even use a jumper instead.

Now we must install two identical SLI-compatible graphics cards into the PCI Express x16 slots. Having installed them, link them through their SLI connectors using a special adapter and attach one of the PSU’s power plugs to the EZ_Plug connector (this last step may not be necessary on other mainboards, but we’re describing the installation procedure for the ASUS A8N-SLI Deluxe mainboard with all the particulars). Fasten the cards to the system case, but don’t forget about the special support that keeps the SLI adapter in place (this step is optional, too). Attach power to the graphics cards, if they require that. Note that a pair of GeForce 6800 Ultra cards needs four Molex connectors, so make sure beforehand your system case has them. Now you only have to plug the monitor’s cable to the graphics card in the top PCI Express x16 slot, and that’s all.

On the next start-up go into the BIOS Setup to check out the SLI Mode option. By default, it is set to “Auto?on the A8N-SLI Deluxe. That is, the mainboard itself determines the necessary mode, depending on the position of the mode selector. If you disable the automatic identification for some reason, make sure the option you select matches the mode set up by the selector.

When Windows XP boots up, you should install the required drivers, including nForce Unified Driver and ForceWare. You can download the latest official versions from the NVIDIA website. If all is done right, the NVIDIA Settings icon on the right of the Windows Taskbar will tell you that the system is ready for the SLI mode by showing a balloon with the text “SLI capable system?after the reboot.

Clicking on this message opens up the SLI multi-GPU dialog window:

You can now click the Enable SLI multi-GPU checkbox and reboot. The Show GPU load balancing option will display an indicator of the load distribution. This indicator is on by default, but you can disable it if you don’t like the green bar on the screen.