Herewith, some preliminary findings from my mad flailing at the new physically based render engine included as an option with DAZ Studio 4.8 Public Beta. Some of these are confirmed by Google, some purely by experiment this evening (Iray is Nvidia's, so it's existed since well before DAZ got hold of it, it's just not widespread yet).
My system specs on my main (not on this laptop I use for internet access):
Windows 7
Intel Core i7-5930K at 3.50 GhZ, 6 cores.
Installed memory: 64 gb
Graphics cards: 2x GTX 740, 2x GTX 980, all 4 gb cards; not in SLI.
For those who are worried, no, Iray is not mandatory, you can still use 3Delight from th