I can't enable SLI on a Windows XP 64 system having a Supermicro X7DWA-N motherboard with two Nvidia Quadro FX 1400 graphics cards. The Nvidia control panel does not show the SLI configuration tab. I used TechPowerUp GPU to verify that SLI is not enabled. I set the performance mode to single display but the SLI is still not enabled. I have the 176.04_quadro_winxp64_english_whq driver installed. How do I enable SLI?
First guess would be your motherboard does not support SLI.
I had this issue myself. After searching the web and banging my head against the wall for the thousandth time (ouch!!! that stings after a while...), i noticed there was a little flip card on the motherboard. It was set to single video card. (Now let me also add that the 18 year old kid at the mom and pop shop had assured me that this little flip card was already set for SLI). So once i set this to SLI where it should've been, there was peace and harmony again in my world. Apocolypse avoided.
Even did a search on the PDF for the mobo for "SLI" and returned nothing.
Thanks for your input. I thought I had researched this thoroughly. The motherboard has two PCI-E slots and supports x16 transfers but I found a note on the support page that it does not support SLI. That's the only reason I bought the motherboard and the two graphics cards, for Cad and Video work. Should have bought a Mac Pro.