Sins of a Solar Empire is an amazing-looking game with the graphics maxed out, but this can be taxing on even newer GPUs. The following is a guide I've made to help those who use NVIDIA's SLI (Scalable Link Interface) technology.

SLI is a feature which allows the rendering of a game or other 3D application by two (or more, but two is pretty standard for now) matching NVIDIA SLI-enabled Graphics Processing Units. While this does not double the user's overall video card RAM (i.e., 2x256 MB cards does not equate to having 512 MB of memory), it usally results in a performance increase of 80-95%. The complexity involved with SLI requires some special hardware and forceware setup, especially because SLI performance depends greatly on the game or application being used.

Step 1: Make sure you have two NVIDIA GPUs that are SLI-compatible and are from the same model series and RAM amount. SLI is most easily done with identical GPUs, but slightly different ones (such as a GTS and a GTX model) have been known to work.

Step 2: Make sure the hardware is correctly configured on your motherboard. You will need an SLI bridge. Detailed installation instructions can be found at http://forums.slizone.com/index.php?showtopic=23245.

Step 3: Make sure you have updated forceware, available from the NVIDIA website if you have a desktop or from your OEM on a laptop.

Step 4: Go into the NVIDIA control panel, open "SLI Configuration," and enable SLI. Note that this is not enabled by defailt.

Step 5: Open the "Manage 3D Settings" section and ensure that your global settings are configured the way you want them, with respect to antialiasing, mipmaps, texture filtering, and so on. Note that the "SLI Performance Mode" is best left set to "Single GPU" in this section.

Unfortunately, the complexity of SLI means that settings must be specifically configured by NVIDIA for each game. There are hundreds of games that NVIDIA has done this for, however, and I have only encountered a few that have not been set up for SLI in the driver software. These are mostly older games, indie games, or non-major foreign games. Sins of a Solar Empire is not (yet?) included in the list of configured games, which you can view in the "Program Settings" tab of "Manage 3D Settings." Thus, you will need to set up a performance profile specific to Sins of a Solar Empire in order to utilize SLI for this game.

Step 6: Open the "Program Settings" tab and click "add." Use the browse function to locate your game directory for Sins of a Solar Empire. Select the game .exe file--NOT the launcher .exe file.

Step 7: A new performance profile will have been created for Sins of a Solar Empire. Scroll down the list to select it. You will see options that are the same as those in "Global Settings." These should be fine for options like texture filtering, antialiasing, and so on.

Step 8: You will need to enable SLI for this game specifically. Scroll down to "SLI Performance Mode," and select the drop-down menu. Because there is no option to custom tweak the SLI settings for this game as NVIDIA does, you will need to select one of the following options:

           Force Alternate Frame Rendering (AFR) 1: This should be your SLI mode, unless problems occur. It gives the greatest overall performance boost.

           Force Alternate Frame Rendering 2: This gives a slightly reduced AFR performance boost, and should help to fix any graphical glitches that occur due to the use of AFR 1.

           Force Split-Frame Rendering: This gives the least of the SLI performance boosts available in this menu, and should be used if the use of any AFR mode causes graphical glitches.

Step 9: Make sure you hit "apply" to finalize the changes, close the NVIDIA control panel, and start Sins of a Solar Empire. If done correctly, this can kick up your framerate by a good 85%. To make sure SLI is working as intended, you can enable the SLI screen display in the control panel: it will show a monitor of the rendering-sharing onscreen when SLI is running--that is, during a game or other SLI-configured 3D application.

Note that this is a temporary fix: hopefully, NVIDIA will get around to customizing SLI settings for Sins of a Solar Empire in a future driver release.

For the record, I force AFR1 for my Sins gameplay. I have all graphics options maxed out and game load times are practically instant with no detectable drop in framerate.

My setup features 2x512 MB NVIDIA Geforce 8800M GTX SLI-enable graphics cards.