I’m using 3ds 2009 and I found this problem using Daylight system with mr Sun and mr Sky with CIE sky model, the final image has a lot of square noisy buckets from rendering.
The other sky models, Haze Driven and Perez All Weather, work fine.
The pc spec are:
Intel Xeon CPU E5520 @ 2.27 GHz 2.39 GHz 16 cores
6.0 GB RAM
NVIDIA GeForce GT 120 256 Mb

	Video

I had similar issues, discussed in THIS THREAD.

Seems there is a bug with MR CIE (or Perez) sky and 5520 CPUs. In the above thread there is a summary table of my tests.

I don’t know of a solution, only a workaround by using Haze model sky instead, but maybe it will save you some wasted time.

-jeff

Max/Composite 2012 (subscription)
Win7-64pro, Intel i7-hex on SuperMicro mobo, 12 GB RAM
nVidia Quadro 5000, render farmette on BB2012

I think the processors have not been around long enough for bugs like this to be addressed.
I did report the FG-Sky rendering issue as a bug on the official Autodesk page.
It would probably help if you could do the same. (thanks!)

The [English] page is the Defect Report Submission Form

-Jeff

Max/Composite 2012 (subscription)
Win7-64pro, Intel i7-hex on SuperMicro mobo, 12 GB RAM
nVidia Quadro 5000, render farmette on BB2012