M080 did not have the OIT option, I checked it when Pepa asked about it.
As far as Dell drivers, that's odd, as I am guessing Dell just repackages the driver with the Dell logo on it. And (at least newer hardware) as far as I know Dell just buys the hardware from Nvidia and slaps it in the computer. So I would think they have no reason to customize the driver? But maybe they do, they are Dell, they don't build them for performance so who knows, maybe they purposely underclock them or software lock the clock or something? I have no idea.