[sliken]

Only if you use dimms. If you use the LPDDR4x-4266 each chip has 2 channels x 16 bits. So the M1 has 4 chips and a total of eight 16 bit wide channels.

[ricebunny]

Does the 8GB variant have all 8 channels or just 4?

[sliken]

My guess is it's the same and using the half density chip in the same family, but I'm just guessing.