When SLI doesn't work for a demo, but the driver has a profile for the 'real' game, the solution is as follows:
1) Go into nVInspector (if you don't have it, GET IT if you run SLI!!!), click the button next to the 'driver' box, and on the next screen, pull up the profile for the 'real' game using the search box. It handles multiple characters being input, which is cool, so just start typing S-P-E and it'll pop right up. If it doesn't, update your drivers cause the SLI profile is there in the latest WHQL drivers (as you can see in my screenie).
2) Click the button at the top whose tooltip says "add application to current profile", just to the right of the red X.
3) Navigate to the .exe for the demo. It *should* NOT match the other .exe names you see in the green bar near the top of the nVInspector screen. The fact that the demo's exe isn't in that list is why SLI isn't working for the demo, IOW.
4) Once you navigate to the .exe for the demo and select it, the green bar should then have the demo's .exe name in it. This means that you've added the demo application to the 'real' game's SLI profile.
Sounds like a bunch of work but it takes like 1 minute, and I'll give you a 99% guarantee that SLI will then work for the demo
I just d/l'd the demo, and it's path is:
And that EXE is NOT in the profile for the regular game, so that's why SLI isn't working on the demo. Note that also AA and anything you change in the NVCP also won't work unless you associate a game .exe with a profile, so it's worth doing even if you don't have SLI. I'm about to try 'forced' 16xAF and 16xQAA + 4xTRSSAA from nvcp, just to see if I can actually get any more than like 30% GPU usage Edited by brettjv - 6/30/12 at 10:19am