The only tweak I made in the Nvidia software is 'single display performance mode' instead of 'multidisplay', because there is only one display. I haven't benchmarked anything, although assume it might matter slightly, possibly not by autodetect features. I don't have the exact detailed knowledge regarding this hardware, capability's and options.
Sofar everything seems to be running fine apart from the 'known' stuffzorz on the map and avoid the very high detailed shadowing.
All HDR settings makes things very blurry, or it's my eyes are having a hard time processing the full context of information being send through photons, so HDR is off for me.
This is what i use to keep performance up, have sharp details and good gameplay with the GTX460.