I'm having the same problem with noise :
This image is from a rendering I did last night. FluidRay RT says that it took 8h 26m. However when I looked at my computer this morning it was hibernating? I looked in on it after a couple of hours last night and it was rendering, so I know that it has been running for that long.
This second image is a small test which took about half an hour I did earlier yesterday. Here the noise is very pronounced :
I'm using an HDR image, resolution 15000 x 7500 pixels in 72 dpi - size 329MB, for lighting the scene. It has 50 in RGB color scaling. Is that the light in the scene?
It is rendered on a Core i7 6700 processor, 4.2 GHz (turbo) with 32 GB of ram.