Logic pro X rosetta 2 box don't appear

Rosetta is needed for Intel-based apps. Logic Pro 10.6 is a Universal app, which means it can run on Intel or Silicon natively.

So if you run Logic Pro on an M1 computer it will automatically run natively in Silicon and there is no need to emulate its Intel code to SIlicon.

Hope that helps,

Edgar R. (as in my "UserName")

Author of the best-selling book series "Graphically Enhanced Manuals" (endorsed by Apple)

It is not often that I can say "you're wrong". It may in fact be the first time.

There is a need for Rosie two in LP 10.6.1: if there are 3rd party plugins that need it.

The only time I saw someone report this, his app was in fact smaller than it should be (how it should be, is shown to the exact byte in my screenshot). I adviced him to reinstall, and the option reappeared.

I did not investigate, but I suspect that some wonky utility (MacKeeper, CleanMyMac?) may have stripped the universal code. His app was roughly 350 MB smaller.

I always like to learn new things and I didn't know that Rosetta is in fact an option for a Universal app on an M1.

However, the information I got from the Logic developers is that any Audio Unit host application that is compiled for Apple Silicon (i.e. Logic Pro) can load any Audio Unit, either compiled for Intel or for Apple Silicon. I haven't tested that yet, but it would mean that you can run Logic natively in Silicon and have Plugins loaded that are either SIlicon native or Intel Plugins, emulated via Rosetta. So no need for Rosetta.

Well, that could be true, since in the mode I've shown, a number of plugins that predate 2019 (and I don't think they made M1 native plugins in 2019 or before) still function - but then why is Rosetta mode there at all?

...and suddenly I remember somebody on YT explaining that you need to open Logic on an M1 once in Rosetta mode to get those plugins "translated", and after that you can turn off Rosie.

Yup, that sounds plausible, and would explain why I have turned it off and still can use "old" plugins.

Like this one:

Eriksimon wrote:

...and suddenly I remember somebody on YT explaining that you need to open Logic on an M1 once in Rosetta mode to get those plugins "translated", and after that you can turn off Rosie.

Yup, that sounds plausible, and would explain why I have turned it off and still can use "old" plugins.

Like this one:

That's interesting. The information I got didn't mention anything of that extra step to have somehow "translated" internally first. Seems kind of clumsy that way, first to know which one requires that step and then re-apply that step if you got another one of those "needy" Rosetta-reliant plugins.

I have to investigate further into that because that is exactly the "devil in the detail" scenario that causes confusion. Don't have a M1 machine yet. My budget committee (aka wife) hasn't approved it yet 😉.

Back to the original question. What is the reason for running a Universal app on a M1 computer in Rosetta mode. There must be a scenario, otherwise, why would that checkbox be there (unless Apple is just messing with us).

BTW, there is a cool utility app ArchiChec that shows what code an app is compiled for. Unfortunately, it doesn't show the code base for plugins.

So you were mostly right after all. :)