[unfasten]

Anandtech has some good 3D NAND info. I'm not positive they answer your specific question, but hopefully it's helpful.

Here are the two articles I remember:

http://www.anandtech.com/show/8216/samsung-ssd-850-pro-128gb... (goes on for a few pages after this one)

http://anandtech.com/show/8747/samsung-ssd-850-evo-review/3 (This is mostly about how 3D NAND benefits TLC)