When it comes to the Linux software side of things, after assembling an SLI system with two GeForce 6600GT solutions, for example purposes, we proceeded to install the BETA 1.0-8168 drivers in the same fashion as previous NVIDIA drivers. After completing the process, SLI needs to be enabled through manually modifying the Xorg configuration or more easily using NVIDIA's new nvidia-xconfig utility. When using nvidia-xconfig, the --sli= flag needs to be specified along with the option of Off, Auto, AFR, SFR, or SLIAA. AFR and SFR are rendering modes presently supported by SLI for Single Frame Rendering and Alternate Frame Rendering. After enabling any SLI mode and then restarting Xorg, the screen will look much the same as previously in a single-card setup along with nvidia-settings, however, there are a few finer points worth mentioning. First off, with nvidia-settings under the graphics card information page, the Bus Type will display the PCI Express speeds for the SLI setup which will be x8 unless using the newer nForce4 X16 Chipset. Next up, under the OpenGL settings page, under miscellaneous the check-box item of Enable SLI Heads-Up-Display. As of yet NVIDIA hasn't implemented any dedicated SLI utility or created any game/application profiles for better benefiting the frame-rate performance of the various OpenGL programs.
The Linux-native games we have ran with this SLI setup are Enemy Territory v2.60, Unreal Tournament 2004 Demo v3334, America's Army v2.5.0, Doom 3 v1.3, Quake 4 v1.0.5, and Mindware Studios Cold War Demo. As you can see from the various screenshots below, Linux SLI is far from perfect as the drivers we used are home to a multitude of bugs hindering the SLI performance. We will stay away from making any decisive comments regarding its performance or usability until the final public drivers are available.
Overall, we are quite thrilled about the recent advancements made to the Linux NVIDIA display drivers as we had viewed with the BETA 1.0-8168 drivers. However, as we have stated numerous times throughout various articles, it will probably take NVIDIA engineers a few driver releases to work out all of the various details related to the SLI performance. As far as hardware goes, it's identical to what is needed for Microsoft Windows; however, it’s simply important to stress the need for a reliable power supply, motherboard, and graphics cards. For more information on SLI, visit SLIZone, which is maintained by the folks at NVIDIA. When it comes to what games will be able to utilize SLI under Linux, you can look for a majority of the retail titles such as Unreal Tournament 2004, Doom 3, Wolfenstein: Enemy Territory, and Quake 4 among others. We have been holding off on publishing any SLI results due to these 1.0-8168 drivers that have quite a few kinks, but upon the official NVIDIA launch, which is expected soon, we will have full coverage with our in-house results. In addition to that, a wealth of other information pertaining to the 1.0-8XXX NVIDIA drivers will be ready.