Question CPU data bit path per memory channel?

[BTRY B 529th FA BN]

How wide is the bit path per memory channel on Vermeer? 128 bit? Therefore dual channel on Vermeer would be a total of 256 bit?

 

[VirtualLarry]

DDR4 DIMMs (non-ECC) are 64-bit. ECC DDR4 is 72-bit. I think.

Dual-channel is x2, and quad-channel is x4.

 

[BTRY B 529th FA BN]

I think Single Rank is 64 bit wide, Dual Rank would be 128 bit wide, but I'm asking about the CPU memory channel width in data bit.

EDIT: DDR4 ICs I think are 8 bit.