Maximum PC

ROUND 1

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RISC vs. CISC

Remember when RISC versus CISC was the battle of the ages? Even today, Intel’s chips and the upstart battalions of ARM processors align according to this paradigm, with x86 CPUs still CISC (or complex instructio­n set computing), and ARM representi­ng the vanguard of RISC (or reduced instructio­n set computing).

But, in practice, it’s a moot point. That’s because ever since the Pentium Pro (and indeed AMD’s K5), x86 processors have really been RISC chips internally, and have relied upon a microcode translatio­n layer to handle the x86 CISC instructio­n set. What’s more, over time, x86 coding has coalesced around a relatively small number of commonly used instructio­ns. All of which means that the old divides that saw x86 chips require relatively complex compilers, along with complex instructio­n scheduling and decoding hardware, and thus a higher transistor count for a given theoretica­l performanc­e capability, not to mention limitation­s on instructio­n pipelining, no longer fully apply. CISC architectu­res, such as ARM, have likewise become more complex, with support for floating point math, virtualiza­tion, and hardware cryptograp­hy. In short, RISC versus CISC is no longer the crucial question.

Winner: It simply doesn’t matter

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