39

Just as the question says: I'm looking for the canonical word on which architecture M1 is.

For when I'm downloading a .dmg to install ....

ie, which one means "ARM" ?

On the command line:

% arch
arm64

My "About This Mac" says:

About Mac

Stewart
  • 625
  • 2
    Should the tile read "amd64" or "arm64"? – nohillside Nov 30 '22 at 10:41
  • @nohillside I copied / pasted it exactly as it was on a download page, offering me a choice of .dmg files – Stewart Nov 30 '22 at 12:39
  • From pcmag: AMD64 is AMD's 64-bit CPUs. Announced in 1999, AMD was first to add 64-bit capability to the x86 architecture with the introduction of the Opteron in 2003. Following very quickly, Intel added AMD's 64-bit architecture to its x86 family (x86-64). – Ricardo Apr 12 '23 at 23:30

2 Answers2

51

Given that choice, the Apple Silicon M1 (and M2) chip is an AArch64 architecture.

AArch64 is another name for ARM64, so it is an ARM architecture.

The AMD64 architecture is what is also known as x86_64, x64 or even Intel 64-bit architecture. This is what you would typically see in slightly older Macs introduced before Apple Silicon.

You can check the architecture of your own computer by opening the Terminal application, and running the following command:

arch

On the M1 chip it will display: arm64

jksoegaard
  • 77,783
  • 4
    AMD stands for Advanced Micro Devices. This is the company that introduced the 64 bit instruction set which was eventually adopted by Intel. – David Anderson Nov 29 '22 at 16:30
  • 2
    Yes, that's why I wrote "even". – jksoegaard Nov 29 '22 at 16:40
  • 5
    Since you mention AMD64, arch on a 2019 iMac returns i386 - not much hint of 64-bit. – Gilby Nov 29 '22 at 21:15
  • 2
    Yes, that's right. Note that the only reason I mentioned AMD64 is that this was the actual question - i.e. OP wanted to know whether M1 was AARCH64 or AMD64. – jksoegaard Nov 29 '22 at 23:20
  • @Gilby I think you can reboot into 64bit mode holding down the 6 and 4 keys. https://superuser.com/questions/23214/why-does-my-mac-os-x-10-6-kernel-run-in-32-bit-mode – John Aug 19 '23 at 00:36
  • @John My Mac is running in 64bit mode. It is just that the arch command returns i386. – Gilby Aug 19 '23 at 06:39
  • Running arch on a 2021 Mac pro also return i386 – liuliang Sep 07 '23 at 12:06
4

For when I'm downloading a .dmg to install ....

ie, which one means "ARM" ?

Any website where you are offered a choice of different installers will/should make it clear which is which, but they need not use 'canonical' terms. Most that I've seen use "Apple Silicon" versus "Intel".

The vast majority of DMGs or PKGs will contain Universal Binaries: that is, a single executable with code for both architectures.

file APPlayMIDI
APPlayMIDI: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64:Mach-O 64-bit executable arm64]
APPlayMIDI (for architecture x86_64):   Mach-O 64-bit executable x86_64
APPlayMIDI (for architecture arm64):   Mach-O 64-bit executable arm64

If there are canonical names for the two architectures, they are arm64 and x86_64.

benwiggy
  • 35,635