[Mihai]

It would help if you describe your scene a little, how you're lighting it, how many bounces etc...

[Mihai]

You're lighting this with the physical sun? Are you using glass in the windows? Because if the light is passing through glass to get to the interior, then all light is caustic light and so it will take MUCH longer to get a clean result.

[Mihai]

What material is on the walls? Diffuse or plastic? Maybe try and make the floor material a simple diffuse to see how that affects the noise. After 9H it should look a bit better than the image you posted. Or did you post the 2H one?

[tom]

nice start

[Maximus3D]

Ain't that pretty or what good job on it and i'm not gonna complain about anything since i can't do a better job myself.

Btw.. noise in renderings is your friend, be nice to it
People always complain about noisy renderings done by Maxwell, yet
those who give such critics they themselves sit in Photoshop adding noise to their own renderings as they're too clean looking. So i say pfffft to them..

Keep on Maxwelling!

/ Max

[Micha]

But what is, if the user want to get a "plastic" floor? A diffuse floor work's, but it is not a professional solution.

Is it possible to use custom object based options (f.ex. disable caustic, receive caustic or create caustic)? I think, a scene with much walls and only one small glass bottle on the table doesn't need caustic in the hole scene.

[Thomas An.]

I do not think the plastic was the source of the noise.

Your time improvement came because you added the emitter in the window. Direct light produces less noise. (Previously all light was indirect).