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Then you don't read right. "Decoding x86 instructions and converting them to the processor's internal microcode ..."
by mankash666 8y ago
Then you don't read right. "Decoding x86 instructions and converting them to the processor's internal microcode ..."
- danmg 8y agoModern x86, for the past 25 years or so, doesn't implement the instructions directly. There's an internal intermediate, proprietary reduced instruction set. So outwardly it's a cisc processor, with variable length instructions and a lot of different instruction modes, but internally it's not.
- monocasa 8y agoAnd even before then they decoded in microcode. That goes all the way back to the 8086, which had five banks of microcode IIRC.
- mankash666 8y agoSpeculation about how an embedded x86 works. Just because their desktop focused, non-power optimized products do something, doesn't necessarily mean their embedded line-up does the same. FYI - Apple is a hard driving customer, they do not compromise on power, performance & cost/pricing
- danmg 8y agoWell, you're up against basic physics here: bigger die required to decode full x86 ISA, more power, more heat.
- tracker1 8y agoBut a 486dx with more integrated cache could be incredibly efficient with modern manufacturing processes. A modern i5-8250 uses under 15W power... we're talking something less than 1/1000 the complexity.
- monocasa 8y agoEvery x86, from 8086 on, has been microcoded.