miskMicrosoft says “Prism” translation layer does for Arm PCs what Rosetta did for Macs
jqubedI don’t really know if ARM adds benefits I’d really notice as an end user, but it’ll be interesting to see if this really goes through and upends the dominant architecture we’ve seen for really 40+ years.
SMillerNLAs an ARM Mac user, I wouldn’t trade all this new battery life for an x86 processor
There’s nothing stopping x86-64 processors from being power efficient. This article is pretty technical but does a really good explanation of why that’s the case: chipsandcheese.com/…/why-x86-doesnt-need-to-die/
It’s just that traditionally Intel and AMD earn most of their money from the server and enterprise sectors where high performance is more important than super low power usage. And even with that, AMD’s Z1 Extreme also gets within striking distance of the M3 at a similar power draw. It also helps that Apple is generally one node ahead.
This article fails to mention the single biggest differentiator between x86 and ARM: their memory models. Considering the sheer amount of everyday software that is going multithreaded, this is a huge issue, and the reason why ARM drastically outperforms x86 running software like modern web browsers.
Do you mind elaborating what is it about the difference on their memory models that makes a difference?
Here is a great article on the topic. Basically, x86 spends a comparatively enormous amount of energy ensuring that its strong memory guarantees are not violated, even in cases where such violations would not affect program behavior. As it turns out, the majority of modern multithreaded programs only occasionally rely on these guarantees, and including special (expensive) instructions to provide these guarantees when necessary is still beneficial for performance/efficiency in the long run.
For additional context, the special sauce behind Apple’s Rosetta 2 is that the M family of SoCs actually implement an x86 memory model mode that is selectively enabled when executing dynamically translated multithreaded x86 programs.
Thanks for the links, they’re really informative. That said, it doesn’t seem to be entirely certain that the extra work done by the x86 arch would incur a comparatively huge difference in energy consumption. Granted, that isn’t really the point of the article. I would love to hear from someone who’s more well versed in CPU design on the impact of it’s memory model. The paper is more interesting with regards to performance but I don’t find it very conclusive since it’s comparing ARM vs TSO on an ARM processor. It does link this paper which seems more relevant to our discussion but a shame that it’s paywalled.