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> x86 is on the way out and can't compete on power or performance. In the end RISC won, it just took a while to get there. What exactly do you think is the fun
by dnautics 6y ago
> x86 is on the way out and can't compete on power or performance. In the end RISC won, it just took a while to get there.
What exactly do you think is the fundamental limitation of x86? Most chips do lot and lots of crazy logic to go from instruction set to microcode, it's hard to imagine that the variable nature of x86 instructions are the limiting factor.
- mhh__ 6y agoAt very least having a big fat decoder costs you power and space, measuring the tradeoff in raw decoder performance is probably dependent on being an engineer working on it at Intel or AMD (or Apple). At very least, Zen 3 is a cutting edge microarchitecture on a cutting edge node with lots of transistors to play with, and it still decodes only half as many instructions per cycle as M1 - an unbelievably wide CPU, which is probably the way forward. The "x86 tax" (if it exists, I guess) is usually estimated at somewhere on the order of 5% to 10% - which is a lot of money at scale but probably not enough for a total rethink.
- waterhouse 6y agoJudging from the M1, it seems the most important thing the big fat decoder costs you is not being able to manufacture billions of processors for small devices (where the decoder would be a much larger fraction of the CPU), develop experience and optimizations and capital based on that, and then have those benefits carry over to your high-end processors.