I think the tech press still tells us what they can, and stuff like execution ports, reorder windows, etc. is still publicly disclosed. AT talked about what was

I think the tech press still tells us what they can, and stuff like execution ports, reorder windows, etc. is still publicly disclosed. AT talked about what was publicly said about Zen 2 (https://www.anandtech.com/show/14525/amd-zen-2-microarchitecture-analysis-ryzen-3000-and-epyc-rome https://www.anandtech.com/show/14525/amd-zen-2-microarchitec...) and Sunny Cove (https://www.anandtech.com/show/14514/examining-intels-ice-lake-microarchitecture-and-sunny-cove https://www.anandtech.com/show/14514/examining-intels-ice-la...). And their reviews do try to report the top observable results (memory latencies, relative performance on different kinds of task, power/clock info) and all that's arguably of more practical importance to lots of folks anyway. There's also just the trend of modern designs being tricky enough it's harder to infer as much about them and harder to write accessibly about what you do know; it's not super easy to figure out and describe, say, modern branch predictors simply because they're all layering a lot of strategies on each other. For example, from Haswell on, Agner Fog essentially said Intel's large-core branch predictors are good at lots of things but there's not much he can say about how they work (p29 at https://www.agner.org/optimize/microarchitecture.pdf https://www.agner.org/optimize/microarchitecture.pdf). Writing code to beat Cortex-A76 prefetchers, AT's Andrei Frumusanu had difficulty fooling them with anything other than essentially-random access patterns and compared them to "black magic" (https://twitter.com/andreif7/status/1102230575522430977 https://twitter.com/andreif7/status/1102230575522430977). These aren't just random folks saying "wow, CPUs are complicated"; they successfully figured lots of stuff about past generations of CPU. AMD did reference the TAGE family of branch predictors, which there's lots about in public literature. There might be some broadly interesting stuff in the vendors' contributions to gcc/LLVM (machine models and arch-specific optimizations). Maybe ARM implementors talk a little more about their stuff? That might have something to do with the dynamics of the relatively open/diverse market for ARM SoCs versus the long-running one-on-one-ish x86 rivalry. Hard to boil all that down to a single point, but if AMD and Intel want to talk more about the guts of their products, I'm sure plenty of grateful wonks would lap it up. :)