[manaskarekar]

Thanks, but just to put things into perspective, this calculation has counted 8 channels which is 4 DIMMs and that's mostly desktops (not dismissing desktops, just highlighting that it's a different beast).

Most laptops will be 2 DIMMS (probably soldered).

[wtallis]

Desktops are two channels of 64 bits, or with DDR5 now four (sub)channels of 32 bits; either way, mainstream desktop platforms have had a total bus width of 128 bits for decades. 8x64 bit channels is only available from server platforms. (Some high-end GPUs have used 512-bit bus widths, and Apple's Max level of processors, but those are with memory types where the individual channels are typically 16 bits.)

[sliken]

I think you are confusing channels and dimms.

The vast majority of any x86 laptop or desktops are 128 bits wide. Often 2x64 bit channels up till last year or so, now 4x32 bit DDR5 in the last year or so. There are some benefits to 4 channels over 2, but generally you are still limited by 128 bits unless you buy a Xeon, Epyc, or Threadripper (or Intel equiv) that are expensive, hot, and don't fit in SFFs or laptops.

So basically the PC world is crazy behind the 256, 512, and 1024 bit wide memory busses apple has offered since the M1 arrived.