[replete]

Looks like the M5 base has LPDDR5x-9600, which works out to 153.6 from base M4's 120GB/s DDR5x-7500. The Pro/Max versions have more memory controllers, 16, 24 and 32 channels accordingly. The 32 channel M5 top-end version will have 614GB/s by my calculations.

It would take 48 channels of DDR5x-9600 to match a 3090's memory bandwidth, so the situation is unlikely to change for a couple of years when DDR6 arrives I guess