What every programmer should know about memory [pdf]

https://stackoverflow.com/questions/8126311/how-much-of-what... Discussion of it in slightly more modern context, worth looking at.

This is an incredibly useful guide, but it starts out with transistor level stuff that I at least find much less relevant. The good stuff starts at section 3, CPU Caches.

Here's a good companion piece that focuses on CPU features rather than memory: "What's new in CPUs since the 80s and how does it affect programmers?"[0] [0]: https://danluu.com/new-cpu-features/

This comes up over and over. It's great. But, the 75% of useful content comes after 25% of diving way too deep into the details of the electrical engineering. "Every programmer" should know the orders of magnitude of cache hierarchy latencies, how RAM loads a whole cache line to service that single byte you requested, roughly how the automatic prefetcher thinks, that MESI and NUMA access are a growing issue, that the TLB cache is a thing, and generally how…