nvidia control panel is okay, but nHancer is much nicer, I have been using it for quite sometime now. It allows tweeking SLI a little better than other programs, and you can switch on the SLI balancing graph and see how your set up runs in game by looking at the graph. For Lock On don't enable any of the OpenGL stuff, make sure you check "Profile can be started manually"check box. Also look in the Tools tab for "Activate Profile" and make sure Lock On is activated, any other profile you check off the enable manually check box will be named in that window too, you can make sure that profile is active before you launch the game. It's supposed to be automatic when the exe is started, but I don't leave anything to chance. :doh: