Did you ever try to use the Xeon Phi? It was hideous to optimize for. The cores were in order. If you've never written code for in order cores, you may not app

Did you ever try to use the Xeon Phi? It was hideous to optimize for. The cores were in order. If you've never written code for in order cores, you may not appreciate exactly how heavily you're leaning on out of order to save your bacon. Things your used to just working suddenly don't. The cores had a 2D layout, but Intel refused to tell you what it was and in practice it was impossible to optimize for. You ended up with variable (as in different on every node) latency for memory access that made programming again painful (and add this to the fact the cores are in order, so you really can't work around the latency). Then there was the software stack that was just odd in some ways. I was researching I/O throughout, and things that just work on any other CPU (on any modern ISA) just didn't behave in a sane way. So yeah, I was not at all sad when Intel cancelled it.