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AndyMacAndMic

macrumors 65816
May 25, 2017
1,112
1,676
Western Europe
Would someone explain to an Apple newbie what Rosetta is?

Warning: huge simplifications ahead! ;)

All the software running now on the Intel based Macs will not run on the Macs with the new M1 chip.
Therefore Apple made a translation layer. This layer makes it possible to run the Intel based software on the M1 chip by translating the 'Intel' code to the 'M1 code'.
Apple calls this translation layer 'Rosetta 2'.
 
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IowaLynn

macrumors 68020
Feb 22, 2015
2,145
589
I need to read article, but it sounds like there is some compiling/optomizing that takes place the first time an application is launched. Will launch faster subsequently.
 

LeeW

macrumors 601
Feb 5, 2017
4,342
9,446
Over here
I need to read article, but it sounds like there is some compiling/optomizing that takes place the first time an application is launched. Will launch faster subsequently.
Correct, the 1st run will take longer but thereafter should appear to run just as it normally would.
 

thehighwaystar

macrumors member
Aug 2, 2018
31
18
It was a Steve Jobs lover in the first years of marriage. He called once a computer Lisa..she got mad...an told him she would tell whole campus they only have sex on prime numbers days of the month and something about his preference ...so afhter long discussion he convinced her he would gonna award her naming a software who always goes from behind any other application while in transaction. (confidence on this...few people know about it)
 

AndyMacAndMic

macrumors 65816
May 25, 2017
1,112
1,676
Western Europe
It was a Steve Jobs lover in the first years of marriage. He called once a computer Lisa..she got mad...an told him she would tell whole campus they only have sex on prime numbers days of the month and something about his preference ...so afhter long discussion he convinced her he would gonna award her naming a software who always goes from behind any other application while in transaction. (confidence on this...few people know about it)
Just Google 'Rosetta stone' instead of telling fantasy stories ;)
 
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Rob9874

macrumors 6502
Jul 19, 2010
406
120
You don't need to. It comes automatically with Big Sur on an M1 computer. You don't have to do anything.
I just got the M1 with Big Sur, and downloaded an app from the App Store that I had purchased previously, and got a pop-up saying that I needed Rosetta to run it and asked if I wanted to install it. Wasn't sure what it was, so I guess I'll install it if I want to run this (and potentially other) Intel-based app.
 

Ethosik

Contributor
Oct 21, 2009
8,142
7,120
Does this only run once per app? Does it translate the app once and its done now? I keep seeing things mentioned when testing x86 games that is running in Rosetta. Is it always running and translating on the fly, or just, in a way, recompiling it type of thing?
 

chabig

macrumors G4
Sep 6, 2002
11,445
9,317
Does this only run once per app? Does it translate the app once and its done now? I keep seeing things mentioned when testing x86 games that is running in Rosetta. Is it always running and translating on the fly, or just, in a way, recompiling it type of thing?
It’s a one time translation. All of the internet stories talking about emulation or “running in Rosetta” are misinformed.
 
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AndyMacAndMic

macrumors 65816
May 25, 2017
1,112
1,676
Western Europe
I just got the M1 with Big Sur, and downloaded an app from the App Store that I had purchased previously, and got a pop-up saying that I needed Rosetta to run it and asked if I wanted to install it. Wasn't sure what it was, so I guess I'll install it if I want to run this (and potentially other) Intel-based app.

Yes. I have read that in other threads too. It seems that in some cases (depending on the version of Big Sur) Rosetta has to be downloaded separately. This is a one time thing. Just install it as the message says. After that you won't notice that it is there anymore.
 
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KPOM

macrumors P6
Oct 23, 2010
18,308
8,320
Does this only run once per app? Does it translate the app once and its done now? I keep seeing things mentioned when testing x86 games that is running in Rosetta. Is it always running and translating on the fly, or just, in a way, recompiling it type of thing?
Most of the time it runs just once, at installation or the first time an app is loaded. However, it is capable of just-in-time translation.
 
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