How many NAND chips are used at a time to get the speeds we see with the extreme?

I know that chips are used in parallel to get the speeds we see with these new SSDs but I always wondered how many were used at once?

In the largest capacity drive there are 64 NAND dies. The controllers are 8 channel and each channel can write to 8 NAND dies so we can write to all 64 NAND dies at once. 

Thanks!!!