Just FYI - The documentation is being diligently worked on.  Several things have been added and more are coming.  :)

Kat

Huh?... Is there a secret documentation page that only select people get to access?  I just checked the Wiki ( http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/render_settings/engine/nvidia_iray/start ) and there's been NO change to it in the months since IRay and Daz 4.8 came out.