Will OS X 10.8 be x64 only?

Discussion in 'OS X Mountain Lion (10.8)' started by marcusj0015, Feb 16, 2012.

  1. macrumors 65816

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  2. macrumors 6502

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    #2
    The efi.boot file in the install disk contains this string; "Unsupported 32-bit-only CPU" ...so probably? haha
     
  3. macrumors 68020

    AbSoluTc

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  4. macrumors regular

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    #4
    correct me if I'm wrong, but was the move to only Core 2 duos and up in Lion primarily to migrate to only 64bit?
     
  5. thread starter macrumors 65816

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    #5
    Thats what I thought, but as the install disk isn't half of the Lion install disk, I was like... wtf?
     
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    maflynn

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    #6
    Apple has been setting the bar, high on this and given the quick progression of CPUs they're fully embracing 64 bit at this time
     
  7. macrumors regular

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    #7
    Not only is it x64 only, it requires a 64-bit kernel which excludes some early Core 2 Duo's.
     
  8. macrumors 68000

    DustinT

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    #8
    Yup. It makes sense, there's good reasons to encourage people to upgrade to newer hardware as the underlying OS changes.
     
  9. macrumors member

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    #9
    I'm not following this... (?)
     
  10. macrumors regular

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    #10
    CPU's aren't just 32-bit or 64-bit. They have lots of technologies that the kernel will take advantage of. I'm guessing there's a technology in the i5/i7 that's required by the kernel, but not available of the C2D.
     
  11. macrumors regular

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    #11
    I found this in another post. Basically, the 64-bit kernel means all your drivers run in 64-bit mode. The firmware on some early macs did not support this unfortunately (or apple just doesn't want to rewrite certain early drivers).

    OS X Mountain Lion requires a Mac with a 64-bit kernel. Mountain Lion supports the following Mac models:
    • iMac (mid 2007 or later)
    • MacBook (13-inch Aluminum, 2008), (13-inch, Early 2009 or later)
    • MacBook Pro (13-inch, Mid-2009 or later), (15-inch, 2.4/2.2 GHz), (17-inch, Late 2007 or later)
    • MacBook Air (Late 2008 or later)
    • Mac Mini (Early 2009 or later)
    • Mac Pro (Early 2008 or later)
    • Xserve (Early 2009)
     
  12. macrumors 601

    GermanyChris

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    #12
    Later C2D had both 64bit processor's and could boot a 64bit kernal. The kernal you can boot to is written in the firware of your computer. Apple writes the firmware, so you machine might be more than capble of running 10.8 but Apple say's it's time for a new one.. Thanks Apple!!
     
  13. macrumors member

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    #13
    Thanks, guys - I follow now. We were referring to mac models by processor. I was being too literal and focusing on the fact that Core 2 processors are 64 bit.

    No problem :)
     
  14. macrumors 68020

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    #14
    How much ram is needed for it to work?
     
  15. thread starter macrumors 65816

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    #15
    He's referring to SSE4 and such ISA extensions. they're basically instructions on the CPU that can make things faster, like how Sandy Bridge has Quick Sync, for transcoding H.264 faster.
     
  16. macrumors 6502a

    Zorn

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    #16
    I wish Microsoft would take after Apple when it comes to their updates. They spend so much time pandering to people with thousand year old machines that the platform stagnates in many regards. It'll be 2020 and Windows whatever will still be coming in a x86 version.
     
  17. macrumors regular

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    #17
    MS's problem is much moreso an unwillingness to break software compatibility. There's little to no advantage in dropping hardware support except where it compromises newer systems in some way (or, in Apple's case, to drive new sales :rolleyes:)
     
  18. macrumors 6502a

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    #18
    It's not only the CPU that decides which kernel it boots, you need EFI32 and EFI64 to boot the 32 and 64 bit kernels respectively, the newer macs have EFI64 and therefore can boot a 64bit kernel and load 64bit drivers, Lion still has a 32bit kernel, it seems Mountain Lion will only have a 64bit kernel.

    There are several Core2Duos that will be able to run Mountain Lion from what i understand, so it's probably the EFI64 part.

    SSE4 is already required by several task, which is why the hackintosh community made a kernel that bypassed those instructions to be able to boot 10.4.x+ on cpus that weren't core duo or core2duo, i had 10.4 running on an ibm with a p4-m.
     
  19. thread starter macrumors 65816

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    #19
    That was an example, I'm well aware that SSE4 is already required.
     
  20. macrumors 6502a

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    #20
    Well they haven't introduced that many instructions lately, and they will still support core2duos and xeons that don't have the exact same instructions as sandy brigde i5/i7 so i'm guessing that's not it.

    With the current DP it seems the issue is an UEFI check since it still has a 32bit kernel, however with Lion the early DPs hadn't migrated to 64bit apps so they could still run in coreduo/solo machines, my guess is by the end of ML development there won't be a 32bit kernel anymore.

    And at this point that's all there is, guessing :S
     
  21. macrumors member

    87racer

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    #21
    This is not correct for now. Apple states that it will be 64-bit only but for now 32-bit mode is still working. In fact, that is the only way to get Parallels working on it for now. Reboot while holding the 3 & 2 keys.
     

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  22. macrumors 6502a

    yeah

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    #22
    OSX 10.8 will be a Hybrid x64-only OS (just like Lion) :)
     
  23. macrumors 68020

    AbSoluTc

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    #23
    The question was "Will ML be x64 only?" - the answer is yes. Now is one thing, upon release is another. That's what people are asking about. The release notes specifically state 64bit only.
     
  24. macrumors regular

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    #24
    So the kernel boot mode will be x64 only. It will still run 32 bit applications, right?
     
  25. macrumors 6502

    Takuro

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    #25
    Yep. 32-bit processes should technically be able to execute on a 64-bit architecture, at least in theory. If an app has dependencies on kexts and frameworks that are no longer available in 32-bit variants, however, it gets more complicated and an app can crash due to resource dependencies.
     

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