"The 21464's origins began in the mid-1990s when computer scientist Joel Emer was inspired by Dean Tullsen's research into simultaneous multithreading (SMT) at the University of Washington."
SMT / Hyperthreading has nothing to do with RISC / CISC or whatever. Its just a feature some people like or don't like.
RISC CPUs (Neoverse E1 / POWER9) can perfectly do SMT if the designers wanted.
Today's CPUs are pipelined, out-of-order, speculative, superscalar, (sometimes) SMT, SIMD, multi-core with MESI-based snooping for cohesive caches. These words actually have meaning (and in particular, describe a particular attribute of performance for modern cores).
RISC or CISC? useful for internet flamewars I guess but I've literally never been able to use either term in a technical discussion.
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I said what I said earlier: this M1 Pro / M1 Max, and the ARM Neoverse cores, are missing SMT, which seems to come standard on every other server-class CPU (POWER9, Intel Skylake-X, AMD EPYC).
Neoverse N1 makes up for it with absurdly high core counts, so maybe its not a big deal. Apple M1 however has very small core counts, I doubt that Apple M1 would be good in a server setting... at least not with this configuration. They'd have to change things dramatically to compete at the higher end.
Intel microcode updates added new machine opcodes to address spectre/meltdown exploits.
On a true RISC, that's not possible.
Or are you going to argue that the venerable POWER-architecture is somehow not "true RISC" ??
https://www.ibm.com/support/pages/checking-aix-protection-ag...
As all CPUs have decided that hardware-accelerated division is a good idea (and in particular: microcoded, single-instruction division makes more sense than spending a bunch of L1 cache on a series of instructions that everyone knows is "just division" and/or "modulo"), microcode just makes sense.
The "/" and "%" operators are just expected on any general purpose CPU these days.
30 years ago, RISC processors didn't implement divide or modulo. Today, all processors, even the "RISC" ones, implement it.
The AWS Graviton are Neoverse cores, which are pretty good, but clearly these Apple-only M1 cores are above-and-beyond.
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That being said: these M1 cores (and Neoverse cores) are missing SMT / Hyperthreading, and a few other features I'd expect in a server product. Servers are fine with the bandwidth/latency tradeoff: more (better) bandwidth but at worse (highter) latencies.