128gb ram

Discussion in 'Mac Pro' started by monkeybagel, Apr 11, 2013.

  1. macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
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    #1
    Is anyone running 128GB of RAM? I understand that OS X will only use 96GB, however other OSs can see the entire 128GB. My concern is, if OS X sees 128 but can only utilize 96GB, will this lead to system instability in OS X?

    Thanks
     
  2. macrumors 6502a

    PowerPCMacMan

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    Jul 17, 2012
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    PowerPC land
    #2
    Hey man, whats up?

    Nah... you have no worries as OS X's cap stops at 96GB... Windows 8 or 7 will allow full 128GB, but what on earth do u need all that memory for?

     
  3. thread starter macrumors 6502a

    monkeybagel

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    #3
    It would be for virtualization labs.
     
  4. macrumors regular

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    San Francisco, CA
    #4
    There was another guy here who had 128 GB RAM installed. He didn't report any issues. And since MacPro's have ECC RAM I wouldn't worry about it too much.

    One thing I would try is installing 128 GB RAM and then making a RAM disk. I believe you can have a 32GB RAM disk AND 96GB of RAM, but no one has confirmed this.
     
  5. macrumors 68030

    wonderspark

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    Oregon
    #5
    Ooh, clever! I'd love to know if this works!
     
  6. macrumors 6502a

    Joined:
    Jun 30, 2011
    #6
    That might have been me. My previous work machine had 128GB thinking either Apple would up the limit or we'd just boot to Linux on occation. Anyway, it runs just fine with 128 plugged in, but only using 96.
     
  7. macrumors 6502a

    Joined:
    Jul 17, 2007
    #7
    I've used way more RAM than that (like taking up the lion's share of a cluster node with a full 1 TB of RAM) at work.

    When working with large data sets or matrices, many languages like R and Python hold them in memory. So for really huge data sets, and analysis done on the full data set, you need massive amounts of RAM.

    There are ways around it - being clever with parallelization and working with your data in chunks, but sometimes its just easier to hurl computational resources at something. Because at the rates I bill for work, if popping 128 GB of RAM into a workstation lets me avoid more than about 2 days of clever coding over the lifetime of the machine, its paid for itself.
     
  8. macrumors newbie

    Joined:
    Dec 19, 2010
    #8
    I'm running 128GB Ram on my 2009 Mac Pro (flashed to 5,1), it runs at 1600Mhz (8x16gb) perfectly.

    However, I'm not running OSX, I'm running Windows Server 2012. I heard in OSX it only shows up as 96GB. But I never ran OSX with the 128GB Ram.

    I don't think it would lead to system instability. But that's just a guess. Sorry I don't know for sure. And I won't be able to test for you (it's a Virtual Machine Server and it runs 24/7, so I can't shut it down to run OSX).
     
  9. macrumors 601

    brand

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    #9
    Just curious why you wouldn't run it on server grade hardware that has dual power supplies and hot swap hard drives, fans, and power supplies.
     
  10. macrumors newbie

    Joined:
    Dec 19, 2010
    #10
    The Mac Pro was laying around and I needed a Computer that can handle a lot of RAM. It's been very robust, enough for my needs :)
     
  11. macrumors 601

    brand

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    #11
    Thanks for the reply and explanation. Do you use it at work or home?
     
  12. macrumors newbie

    Joined:
    Dec 19, 2010
    #12
    Sure thing, hehe, we're running away from the OP's question :)

    To answer your question: I use it at the office. Love it!
     
  13. thread starter macrumors 6502a

    monkeybagel

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    #13
    Why did you elect to go with Windows Server 2012 over ESXi/vSphere?
     
  14. macrumors 601

    brand

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    #14
    Usually cost is the number one reason for that. The licensing for the VMware environment I manage at work is $30k+. Additionally with the way Microsoft changed their licensing model for Server 2012 Datacenter making the operating systems for the Server 2012 virtual machines running on a Server 2012 Datacenter host now covered by the host license. That saves even more money and the more VMs you run the more you save.

    We also use Veeam so there is a large cost there also but that cost would be there with HyperV too, if you choose to use it.
     
  15. thread starter macrumors 6502a

    monkeybagel

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    #15
    You must have the Enterprise Plus licenses.

    I don't know anyone that uses HyperV in production was the reason I was asking. It is probably stable for Windows VMs, but VMware ESX/ESXi has been really at the "appliance-level" reliability at some time. In low security environments, the uptime on ESXi is very impressive and with the small attack footprint patches are not as critical as other platforms. In high-security environments with vMotion, I have been very impressed with what VMware brings to the table. I think the Mac Pro is even a supported platform for ESXi 5.1.
     
  16. macrumors newbie

    Joined:
    Dec 19, 2010
    #16
    The VMs are actually running for development/testing environment. So yes, they are running 24/7 because other people access them too, but if it crashes, no big deal. Definitely not production :)

    Windows Server 2012 with HyperV is more than I need. It was all part of the MSDN subscription I have access to
     
  17. thread starter macrumors 6502a

    monkeybagel

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    #17
    I guess since I started the thread, I can wander off topic :)

    Are they all Windows VMs?

    I have installed Hyper-V and Windows Server 2012 with the Hyper-V role in a test environment, but I am honestly biased because I have used VMware Workstation since 2.0 and ESX since 3.0, and have had nothing but wonderful results. I would like to know more about people's experience with Hyper-V and if they are happy with it, etc.

    From what I understand, it is a good platform for Windows VMs, but not quite as good for *nix VMs.

    You have peaked my interest - I may install it on this Mac Pro and see how well the VMs run. :)
     
  18. macrumors newbie

    Joined:
    Dec 19, 2010
    #18

    Hehehe! Of course :)

    Yeah, I only use Windows VMs. Everything from Windows XP to Windows Server 2012. It works like a dream, smooth, easy to configure, snapshots work as expect. Of course, I don't have anything to compare it with other than VMware Server 2.0 that I used to use back in the days.

    Windows Server 2012 runs as well on the Mac Pro as any other PC desktop. The only nicer thing is that it has enough slots of 128GB of Ram. Which is really really sweet when you need it!

    Like it said, I used my Mac Pro because it was laying around; it was not the designed purchase.

    let me know how it goes!
     
  19. macrumors newbie

    Joined:
    Apr 16, 2013
    #19
    I just signed up to add my $.02 on the wandering topic. :) We use VMWare extensively here and had positive results. I looked into Hyper-V using SCOM (similar to vCenter) but it required too much effort to replicate something we already have and invested with VMWare/vCenter. When I have time, I do need to look back again though. And just like what OP said, VMWare does offer support for various platforms and we run them all (Windows, Linux, Solaris). Now we're looking to virtualize the Mac platform using a Mac Pro.

    Anyway, I came across this thread because I wanted to know since Apple only configures its Mac Pro to a max 64GB, I guess the only option is to go 3rd party vendor/supplier?
     
  20. macrumors 65816

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    #20
    I participated in a focus group type thing a while back. The company is working on a bare metal hypervisor for Macs. It was pretty impressive. Especially since it was very minimal code. I think they said 16k of code?
    VMs ran very fast. Though I did miss more advanced virtual networking features you see in other hypervisors.
     
  21. thread starter macrumors 6502a

    monkeybagel

    Joined:
    Jul 24, 2011
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    United States
    #21
    Yes. I personally don't understand why (and would like to) but Apple has in almost all cases quoted a conservative amount of RAM their machines can hold. In a dual socket Mac Pro, the stated amount is 64GB, however 128GB has been tested and works fine with 16GB modules. A single socket Mac Pro will max out lower than that.

    A theory is that when the hardware is designed an manufactured by Apple, only certain RAM modules were available at the time (i.e. 8GB) but as technology progresses Apple does not update their specifications that their products do indeed support 16GB modules. I am not sure if that is the actual case or not, though.
     
  22. macrumors regular

    Joined:
    Feb 1, 2013
    #22
    I think manuals only specify what was/is offered by Apple. If they update the offer through firmware update, Apple Store update, etc, they'll update their manuals (online, or with new models). Apple say that Mac Pro can handle 64 GB because it's the best upgrade you can buy through them (as they don't sell 16 GB stick), although the OS support up to 96 GB. If you buy external RAM, which isn't necessarily certified by Apple, but tested to work and following the Apple specs (any RAM should work anyway), you'll go outside what Apple IS certifying to work. They mostly certify only what they sell.

    e.g. http://support.apple.com/kb/ht1219 The Xserve RAID wasn't offered with 750 GB hard drives when released, but, as it was added through firmware update, the specs have been updated (with a note indicating the firmware 1.5.1 requirement).

    Apple never supported officially 16 GB sticks, so, they'll continue to say that the maximum is 64 GB.
     
  23. macrumors 65816

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    #23
    Most motherboard manufacturers are also conservative about spec-ing max ram. Ram modules draw current, higher density modules draw more current. This is why Apple and other companies may err on the conservative side. It's better to say with confidence that you can pull off 64gb than say 128gb is good but be on a narrower margin of safety.
    And then there is the Mac Pros infamous finickyness when it comes to ram. I cant think of any other server or workstation that is so picky about ram!
    I quite often must buy whole sets of ram at a time because even different batches of the same model ram won't play nice.
    Not sure why Macs are so NOT plug and play in the ram dept.
    (pretty frustrating too, I have a whole tray of 1 and 2gb modules that aren't being used)
     
  24. macrumors regular

    Joined:
    Aug 17, 2010
    #24
    I got 48gb on board sorry not 128gb :)
    But, making extra DRAM into a ram disk for scratch disk, has let my multi camera (i got 5 angle of cameras sequence) editing in Premiere Pro CS6 like flying. Before I made the ram disk, I used SSD, but it will shatter.

    So extra ram does help!!
     

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