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A comment on Testing AMD's Bergamo: Zen 4c. Parent comment

Re:Testing AMD's Bergamo: Zen 4c by jorvi on Sunday June 23, 2024 @10:26AM (#40767697)
Chips and Cheese specifically talks about this in the article I mention[0].

x86 decoders take a tiny but still significant silicon and power budget, usually somewhere between 3-7%. Not a terrible cost to pay, but if legacy is your only reason, why keep doing so? It’s extra watts and silicon you could dedicate to something else.

[0] https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-...

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Re:Testing AMD's Bergamo: Zen 4c by antonkochubey on Sunday June 23, 2024 @05:07PM (#40770592)
But decoders for e.g. ARM are not free either, right? Or am I misunderstanding something?
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Re:Testing AMD's Bergamo: Zen 4c by jorvi on Sunday June 23, 2024 @05:56PM (#40770930)
Correct. However because ARM has fixed-length instructions the decoder can make more assumptions, keeping the decoder simpler.

Like I said, you its only a small amount of extra silicon you’re paying the x86 tax with, but with the world mostly becoming ARM-compatible, there’s no more reason to pay it.

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