What's the difference between the mental ray parameters & iray parameters?

[purified]

My understanding is that in order to use iray, you should set up the mental ray rendering parameters. (as if you are gonna render with mental ray)
Then, you switch to iray and hit the render button.
Am I right?
Or, are they totally different?
Do you have to set up your new settings with iray from scratch? regardless of mental ray's parameters.

[maxt]

RTFM ;-)

ps: option settings ..

[Remydrh]

As Max explains, it's in the Max documents, however it's not in other packages.

What are you using iRay in?

There is a sticky in the Maya forum explaining iRay usage there.