Because of SI's poor foresight, direct links don't work to the page, but as the others post say it's easy to find once you get to the support site. Also note that the 3112 and 3112 RAID are two different drivers, and your controller needs the RAID version. Do not use the vanilla 3112 drivers which would result in BSOD upon next boot or similar. The vanilla drivers are version 1.00.52 last I checked, and the RAID drivers which you need are verison 1.00.50. If you haven't updated your mobo BIOS in a while, you may have to update it before installing newer RAID drivers, as the controller's BIOS is updated through that process as well and newer drivers require a certain base BIOS version for the controller.
edit- Auric, how did you do that? What kind of voodoo are you sporting :Q