I had big problems with SLI on my GTX 690 during the open beta. I tried every fix avaiable (Nvidia inspector etc.).

Today I purchased my copy of the game and since I live in Norway, I can't play before Thursday 00:01. So I tried FLYVPN on Origin (it worked) and played about 10 minutes of the campaign. I had everything on very high except AA disabled, textures at high and lens flares at high. I got about 40-80 FPS, when it was about 80 FPS I looked down in the ground or up in the air.

Both of the cores were below 50%, the most I could see was 41%.

After those 10 minutes I turned off flyvpn, deleted the exe and relogged into Origin. So now I have to wait till Thursday, but now I know SLI is working.