Any time somebody mentions the Pentium 4, it feels like a peek at a time-line we didn’t end up going down. Imagine if Intel had stuck to their guns, maybe they could have pushed through and we’d have CPUs with ridiculous 90 stage pipelines, and like 4 threads per core. Maybe frameworks, languages, and programmer experience would have conspired to help write programs with threads that work together very closely, taking advantage of the shared cache of the hyperthreads.

I mean, it obviously didn’t happen, but it is fun to wonder about.