Mac OS Versions

What versions/architectures are supported at CSAIL?

  • Mac OS 10.5 "Leopard" and earlier -- no support
  • Mac OS 10.6 "Snow Leopard" -- no support (recommend upgrade to at least 10.8)
  • Mac OS 10.7 "Lion" -- full support
  • Mac OS 10.8 "Mountain Lion" -- full support
  • Mac OS 10.9 "Mavericks" -- full support

Background on "architecture" (Intel 32- and 64-bit, also PowerPC)

  • Macs made before ~2006 use PowerPC processors.[1] Modern programs may not work on these computers; "Universal" programs, that include both PowerPC and Intel code, will.
  • Macs made since ~2006 use Intel processors.
  • All Macs made since ~2008 can run both 32-bit (aka x86) and 64-bit (aka x86_64) Intel programs, using Mac OS 10.5 or 10.6.
  • Some Macs made since ~2010 boot to a 64-bit Mac OS kernel by default, which makes little practical difference except triggering some bugs (such as slow AFS performance.)

See Wikipedia's listing to find the processor of a particular Mac model. See Apple's support document to determine whether your model boots a 32-bit or 64-bit kernel by default, and how to change that if necessary.

[1] Yes, if you want to get historical, it's more complicated than that.

What version/architecture am I running?

  1. Apple Menu -> About this Mac
  2. Version: Near the top, look for "Version 10. ..."
    • Version starting with 10.5 is also called "Leopard"
    • Version starting with 10.6 is also called "Snow Leopard"
  3. Architecture: Next to "Processor", look for "Intel" or "PowerPC"
  4. Kernel: Click "More Info..." -> "Software". Look for "64-bit Kernel and Extensions: Yes/No."
Topic revision: 10 Jul 2014, JasonDorfman

MIT Computer Science and Artificial Intelligence Laboratory


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