Hair Display in NVDFIA Iray.

Simple question.....I hope
The viewport is NVDFIA Iray.
Quite simply how do I get "force" hair to displa the way it will finally render
It shows correctly in Textures shaded
Source of frustratio. Not animating, just still image
Comments
What sort of hair - modelled or dForce/stand based hair?
Sorry dforce/strand based
Thank you
The settings that control are in the Line Tessellation group in the Parameters pane.
My thanks
My workflow has increased a lot.......thanks to you.......as usual