It's pretty weird to think that x86 gives Intel any advantage over ARM.
Let's see: x86 code density is horrible for a CISC, there is hardly any advantage over ARM, which does great being a RISC. Also remember that the memory bandwidth is primarily a problem for data, but not code. ARM64 is a brand new ISA, it's the x86 ISA that is a relict from the times when processors were programmed with microcode. Intel is doing a great job to handle all this baggage, but to claim that the ISA gives Intel an advantage is ridiculous.
And finally, Linus has been an Intel fanboy since day one. Go read the USENET archives to find out. He received quite a bit of critique because the first versions of Linux were not portable but tied to i386.
x86 code density may not be optimal but it's better than regular ARM - only thumb-mode can beat it, and just barely.
> Also remember that the memory bandwidth is primarily a problem for data, but not code
RISCs, by design, need to bring the data into the processor for processing; but I see things like http://en.wikipedia.org/wiki/Computational_RAM being more widely used in the future, where the computation is brought to the data, and this becomes much easier to fit to a CISC like the x86 with its ability to operate on data in memory directly with a single instruction. Currently this is done with implicit reads/writes, but what I'm saying is that the hardware can then optimise these instructions however it likes.
The underlying principle is that breaking down complex operations into a series of simpler ones is easy, combining a series of simpler operations into a complex one, once hardware can handle doing the complex one faster, is much harder. x86 lagged behind in performance at the beginning because of a sequential microsequencer, but once Intel figured out how to parallelise that with the P6, they leapt ahead.
Linus being an Intel fanboy has nothing to do with whether x86 has an advantage or not. But even if you look at cross-CPU benchmarks like SPEC, x86 is consistently at the top of per-thread per-GHz performance, beating out the SPARCs and POWERs, and those are high performance, very expensive RISCs. I'd really like to see whether AMD's ARMs can do better than that.
Let's see: x86 code density is horrible for a CISC, there is hardly any advantage over ARM, which does great being a RISC. Also remember that the memory bandwidth is primarily a problem for data, but not code. ARM64 is a brand new ISA, it's the x86 ISA that is a relict from the times when processors were programmed with microcode. Intel is doing a great job to handle all this baggage, but to claim that the ISA gives Intel an advantage is ridiculous.
And finally, Linus has been an Intel fanboy since day one. Go read the USENET archives to find out. He received quite a bit of critique because the first versions of Linux were not portable but tied to i386.