The first is the timings, which is nominally real but it was never a huge difference. Moreover, the new CAMM standard aims to address this and basically does. The legacy SODIMM standard wasn't great and is essentially what caused this.
The second is the bus width. If you use slotted memory and want a wide bus then you need at least one slot per channel and then you could end up needing a lot of slots. This isn't impossible -- servers do it -- but there is a cost attached to it.
But this doesn't apply to systems that aren't using a wide bus. The base M3 has the same bus width as ordinary dual-channel PCs. The Pro has the equivalent of four channels or, for the newer generation, three. That's still not a crazy number in a high end system. With CAMM it would only be two modules, since the modules are each 128-bit. By way of comparison, Threadripper has four or eight channels and modern servers have dozens.
The first is the timings, which is nominally real but it was never a huge difference. Moreover, the new CAMM standard aims to address this and basically does. The legacy SODIMM standard wasn't great and is essentially what caused this.
The second is the bus width. If you use slotted memory and want a wide bus then you need at least one slot per channel and then you could end up needing a lot of slots. This isn't impossible -- servers do it -- but there is a cost attached to it.
But this doesn't apply to systems that aren't using a wide bus. The base M3 has the same bus width as ordinary dual-channel PCs. The Pro has the equivalent of four channels or, for the newer generation, three. That's still not a crazy number in a high end system. With CAMM it would only be two modules, since the modules are each 128-bit. By way of comparison, Threadripper has four or eight channels and modern servers have dozens.