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I don't think you can single out one aspect when comparing designs which are so different, but I'd say most of the CPU performance is down to the core. There yo

I don't think you can single out one aspect when comparing designs which are so different, but I'd say most of the CPU performance is down to the core. There you have the M1 core which is (iirc) 10 pipes wide, much wider than both AMD and Intel, and a much fatter frontend as well to feed the beast. I think that's the main advantage the M1 has. It also has a larger L1 cache (twice as big as x86). These two are one of the few areas where x86 has an innate disadvantage because fattening up the frontend is much more complex on x86 compared to ARM, and you can't have a VIPT L1 cache larger than 64K with 4K pages, which is a hard-to-change default on x86, while the M1 by default uses larger pages (32K or something like that).

errantspark 5y ago
"x86 has an innate disadvantage [...] fattening up the frontend" this is inherent largely because of ISA complexity and variable width instructions? "M1 core which is [...] much wider than both AMD and Intel" The core width you're referring to is the decoder width yeah? As another poster pointed out the M1 has a large reorder buffer as well. Combined with the ability to index a larger L1 cache what I'm getting here is that the M1 can be a lot better about scheduling instructions (and perhaps even running non-interfering instructions in parallel on a given core (is that a thing?)) because the frontend has more power and space to do so. I guess that efficiency is then a big part of the puzzle on why the increased bandwidth to ram makes such an impact?