Gtx690::Both GPU's do get used, i checked.

Testing Asus GTX690, not techi, but thought to share that, according to MSI After burner GPU utilisation graph, both GPU's of the 690 do get used.

GPU 0 gets most of the work, soon as i take off, start getting into clouds etc, second GPU kicks in big time.

Only done very little testing so far, but yeh smooth.

Previously purchased EVGA 680, but that was threating to erupt like a volcano with 4XSGSS, 690 cooling much better. But only tested with 2 SGSS so far.

Not sure if its in SLI or not, just ticked a box saying Max3D performance mode, this mode uses both GPU's.

Got 2 screens 40inch, 23inch. 23inc for panels 40inch main screen.

There is a 690 review here on AVSIm which says Vsync, does not work with SLI, atleast for him.

Had to enable Anti aliasing in FSX, getting shimmering with Word Not Allowed setting i used for 680 which was ok. But FSX Anti alias seems to work better for 690. Maybe will remove the Vsync tweak as well see what happens.

Would be nice to know what inspector settings recomended for this, but i do have starting point with the 690 review here in avsim.

But the main point is, both GPU's do get used, and 690 much cooler than 680.

As for OC this expensive card, very gently over long period slowly raising the sliders, ever so gently.

One more tip, best to use GPU fan speed curve of your own in MSI, very helpfull to keep temps down for 680. If you draw right curve for fan response it helps the OC.