x86 vs. ARM is irrelevant, that's just the instruction set. There's (almost) no performance or efficiency differences from the instruction set by itself.

Apple's particular ARM CPU core happens to look like a beast vs. Intel's particular x86 CPU core. But those are far from the only implementations. AMD's x86 is, at the moment, also very strong, and incredibly efficient. Lookup Zephyrus G14 reviews for example - the AMD 4800HS in that is crazy fast & efficient vs. comparable Intel laptops.

Similarly, lookup Apple A12/A13 vs. Qualcomm benchmarks - Snapdragon is also ARM, but it kinda sucks vs. Apple's A12/A13.

In terms of power realize that there's quite a bit of overlap here. Apple's big cores on the A13 pull about 5W. That's not really that different from X86 CPU cores at similar frequencies. The quad-core i5 in a macbook air, for example, pulls around 10w sustained. It's just a product design question on what the power draw stops at. More power = more performance, so usually if you can afford the power you spend it. So far there's been relatively little product overlap between x86 & ARM. Where there has been, like the recent ARM server push, power consumption differences tend to immediately go away. Laptops will be a _very_ interesting battle ground here, though, as differences get amplified.

I thought RISC chips are easier to create in a more power efficient way as the chip design is way easier than for CISC (like x86)? If Apple had been able to create a competitive x86 chip they would've done that. But the instruction set is an extremely important part of that.

Please no - that debate is an anachronism.

Apple simply can't create any kind of x86 chip whatsoever (at least if they plan to use it :) ) - they don't have an ISA license and likely won't ever be able buy one, because Intel doesn't sell.

Well, apart from outright buying AMD. Or Intel. Or both. :)

So you basically say it's not hard to design a processor (even x86), just patents prohibit it? I had always thought that at least some part of the Intel/AMD dominance was the complexity of the designs and manufacturing that even a company like Apple couldn't build within a decade.