[zeusk]

> Many (most? citation needed) current, mainstream CPUs use the same bit width for all three (address, data, register).

This is quite wrong, for most x86_64 processors:

Address bus is 42-48 bits

Data bus is 32-128 bits

Registers are 64 bits but usable as 32/16/8 bits

Even on most ARM processors, neither the address bus nor the data bus are same width as either or the register width.

[fanf2]

Don’t forget the SIMD registers which can be 128/256/512 wide (neon/avx2/avx512)

It’s very difficult to give just a single number for data bus width. Do you add all the DRAM channels? DDR5 has 2 x 32 bit channels where DDR4 has a 64 bit channel. What does bus width mean for PCIe, which uses very fast differential serial lines? Really, it hasn’t been a useful way to describe system performance since the 1990s.

[daggersandscars]

Awesome! Thank you for posting this. I'd edit my response to include this, but it's too late.