The M1 still uses DDR memory at the end of the day, it's just physically closer to the core. This is in contrast to L3 which is actual SRAM on the core.
The DDR being closer to the core may or may not allow the memory to run at higher speeds due to better signal integrity, but you can purchase DDR4-5333 today whereas the M1 uses 4266.
The real advantage is the M1 Max uses 8 channels, which is impressive considering that's as many as an AMD EPYC, but operates at like twice the speed at the same time.
The DDR being closer to the core may or may not allow the memory to run at higher speeds due to better signal integrity, but you can purchase DDR4-5333 today whereas the M1 uses 4266.
The real advantage is the M1 Max uses 8 channels, which is impressive considering that's as many as an AMD EPYC, but operates at like twice the speed at the same time.