this isn't about Harvard/VonNeuman split/no-split between i-cache and d-cache

I think this post is more about... compute in memory? if I got it right?

Here is John Backus' original paper[0], which is an easy read, but note what he calls functional programming_ has nothing to do with lambda calculus, Haskel etc... it is the APL family.

He is absolutely one of IBM's historical rockstars. IMHO they are invoking him to sell their NorthPole chips which have on-die memory distributed between the processing components and probably has value.

> In its simplest form a von Neumann computer has three parts: a central processing unit (or CPU), a store, and a connecting tube that can transmit a single word between the CPU and the store (and send an address to the store). I propose to call this tube the yon Neumann bottleneck. The task of a program is to change the contents of the store in some major way; when one considers that this task must be accomplished entirely by pumping single words back and forth through the von Neumann bottleneck, the reason for its name becomes clear.

IMHO IBM is invoking John Backus' work to sell what may be an absolutely great product but are really just ASICs and don't relate to his machine or programming language limits.

[0] https://dl.acm.org/doi/pdf/10.1145/359576.359579

Sort of? It's about locality of data; this has often been a bottleneck, which is why we have CPU caches to keep data extremely close to the CPU cores with practically zero latency and throughput limitations compared to fetching from main memory. Unfortunately now we're shuffling terabytes of data through our algorithms and the CPU spends a huge amount of its time waiting for the next batch of data to come in through the pipe.

This is, IIRC, part of why Apple's M-series chips are as performant as they are: they not only have a unified memory architecture which eliminates the need to copy data from CPU main memory to GPU or NPU main memory to operate on it (and then copy the result back) but the RAM being on the package means that it's slightly "more local" and the memory channels can be optimized for the system they're going to be connected to.