RAM beyond 32 GIGs

Discussion in 'Mac Pro' started by IceMacMac, Mar 12, 2011.

  1. IceMacMac macrumors 6502

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    #1
    Curious if anyone here enjoys more RAM than 32 GIGs.

    I find that AE requires up to 3 gig per CPU/thread, plus application RAM, and RAM reserved for the system and other apps.

    I also often find myself with the following apps all open at once:
    AE
    c4d
    PSD
    Illustrator
    iTunes
    Safari

    For this reason I'm considering jumping to 48 GIGs.

    Anyone have experiences or expectations?
     
  2. beto2k7 macrumors 6502

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    #2
    Owc has been able to run a dual processor (2009/2010) Mac pro wit 64GB so yeah
     
  3. IceMacMac thread starter macrumors 6502

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    #3
    It's been possible for a long time now. I just am curious about people's experiences.
     
  4. Vylen macrumors 65816

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    #4
    I don't know what you're expecting in terms of experiences... since it just works, you just put the RAM in and turn the computer on. It'd be no different from a person upgrading to 32GB of RAM after figuring out that it's how much they need.
     
  5. Hellhammer Moderator

    Hellhammer

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    #5
    Just to remind that IIRC you have to boot into 64-bit kernel to utilize more than 32GB of RAM. Absolutely not an issue but I'm only reminding.
     
  6. mulo macrumors 68020

    mulo

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    isn't that default on the newer mac pros?
     
  7. IceMacMac thread starter macrumors 6502

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    #7
    No, it isn't remotely that simple. If you were an After Effects user you'd appreciate what I'm saying. With AE's quirky 64 bit implementation the RAM requirements and how you set up your app's memory/CPU preferernces change in all kinds of unexpected ways as you scale up in the qty of CPUs.

    There are many real world gotchas and certain sweet spots. In Friday's MacPerformance Guide the author makes a big point about how "16GB makes all the difference in big jobs" for Photo pros. There is a big jump from 4 to 8...and another big jump from 8 to 16.

    And things don't scale evenly at all. PTGui for instance saw a 250% speed increase when going from 8GB to 16GB of RAM.

    Contrastively, we've all seen how there are many times when specs don't translate to much real-world difference. So I'm not asking a simplistic or trivial question by any stretch of imagination.
     
  8. Hellhammer Moderator

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    #8
    Yeah, but OP has 2009 Mac Pro according to his sig.
     
  9. IceMacMac, Mar 13, 2011
    Last edited by a moderator: Mar 13, 2011

    IceMacMac thread starter macrumors 6502

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    #9
    That is something I did not know, and should consider. I do a lot of Flash work and don't believe it is 64 bit.

    Would booting into 64 bit break my 32 apps...or would they run in some reduced or virtualized mode?

    Correct. The 2009 Mac Pro is the machine I'm considering upgrading.

    I'm also considering just setting the upgrade money aside towards a 2011 Mac Pro and it's related peripherals.
     
  10. Hellhammer Moderator

    Hellhammer

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    #10
    There is nothing to worry about. 64-bit kernel can run 32-bit apps fine, like your current 32-bit kernel can run 64-bit apps. I mainly said it because if you install +32GB of RAM without 64-bit kernel, the extra RAM wouldn't be utilized, so I just said it to avoid future confusion (OWC says this on their site too).
     
  11. IceMacMac thread starter macrumors 6502

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    As I think about it...I've got to be running in 64 bit now. The majority of apps/processes in Activity Monitor are showing that they are running in 64 bit.
     
  12. Vylen macrumors 65816

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    #12
    That's not how you find out if you're running a 64-bit kernel.

    Running 64-bit applications in OS X is independent of running either a 32-bit or 64-bit kernel.

    To know for sure, from the Apple support page:
     
  13. Hellhammer Moderator

    Hellhammer

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    #13
    Or if the kernel_task is 64-bit in Activity Monitor.
     
  14. IceMacMac thread starter macrumors 6502

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    #14

    OK, thanks Vylen!

    It looks like I'm booted in 32 bit.

    This raises a whole new set of questions: Would I be better served running in 64 bit mode now? (Performance/Stability)

    I'll have to try it out tomorrow.
     
  15. gullySn0wCat macrumors 6502

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    #15
    Try it. If you get kernel panics that you weren't before, it means you have 32bit kexts. Find out which one is causing the kp and see if there is a 64bit version available.

    Otherwise, there will be no difference (other than being able to install something like a few terabytes of RAM ;-))
     
  16. mulo macrumors 68020

    mulo

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    #16
    no, 32 bit kexts wil be disabled automatically
     
  17. gullySn0wCat macrumors 6502

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    #17
    Really? I have heard stories of some printer kexts causing KP on the new MBPs?
     
  18. Garamond macrumors regular

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    #18
    I went for 64GB from OWC, with no regrets. My RAM usage has yet to surpass 50GB, but since the amount of used memory lies between 30 and 40GB I'm glad I didn't settle with 32. With that in mind the best would have been 48 for my use. Anyway, my rig is quite "future-proof", for some years at least.
     
  19. IceMacMac thread starter macrumors 6502

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    #19
    Awesome...someone w/real world experience. Yes I'm thinking about 48. I don't think I'd use 64 yet.
     
  20. mulo macrumors 68020

    mulo

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    i simply cannot fathom how you guys can use that much ram :p
     
  21. IceMacMac thread starter macrumors 6502

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    #21
    It's all a matter of the apps you use.

    If you take a quick scan of Adobe's own Todd Kopriva's RAM recommendations you'll quickly realize that to utilize most of the MP's CPUs available you need considerably more than 32 gigs of RAM.

    And if you often are bouncing in and out of AE into Photoshop and c4d...it gets intensive.
     
  22. Hellhammer Moderator

    Hellhammer

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    #22
    Read the OP. If AE requires about 3GB of RAM per CPU thread, that is up to 48GB with 8 cores/16 threads. And that is just AE. Throw in some other apps and system and you will be using tens of GBs of RAM.
     
  23. mulo macrumors 68020

    mulo

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    #23
    I never understood this ram pr thread thing..
     
  24. IceMacMac thread starter macrumors 6502

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    #24
    A thread, IIRC, is just another term for a CPU, but the term thread includes virtual CPUs.

    Unlike 3d apps which seem to be far more efficient at multi-processor rendering, AE basically spawns clones of itself to handle rendering multiple frames at the same time. It's like having 4 or 8 or 12 (whatever) copies of the program open at the same time.
     
  25. derbothaus, Mar 14, 2011
    Last edited: Mar 14, 2011

    derbothaus macrumors 601

    derbothaus

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    #25
    This is not true. Sorry.
    A thread is an execution unit. Kind of like an atom to a CPU. They are scheduled, then processed. Hyper threading gives the ability to schedule 2 threads per cpu core instead of the one.
    They are not "part" of the cpu in any way. Nor does anyone call a cpu a thread or use thread to refer to virtual processors. For lack of a better analogy, a thread is digested by the cpu.
    http://en.wikipedia.org/wiki/Thread_(computer_science)
     

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