Question: nMP (6.1) equipped with 128GB RAM ?

Discussion in 'Mac Pro' started by Gordon Shamway, Nov 20, 2015.

  1. Gordon Shamway macrumors newbie

    Nov 20, 2015
    Hi folks,

    I’m actually in the process of changing my current setup (music production), which now contains three MacPro’s ( Models 3.1 / 5.1 ), one of them is functioning as Master , the other two as Slave-machines. Because having lots of RAM available is essential for my workflow , each machine is equipped with 32GB RAM / 48 GB RAM .

    For various reasons I decided to switch in the near future to the new MacPro (6.1) model, plus a Windows Slave. (I won’t wait for a possible nMP 7.1 release, because I need a new setup right now.)

    I’m aware that the available 32GB RAM sticks for the nMP are clocked at 1066MHz
    ( ) , which is not an issue for me.​

    However, so far I haven’t found any “real world” reports about using the nMP equipped
    with an 128GB RAM kit.
    Are there any (known) issues with using the MacPro(2013) with 128GB RAM ? Any hints ?​

    Thanks a lot for any infos on this topic,

  2. Zwhaler, Nov 20, 2015
    Last edited: Nov 20, 2015

    Zwhaler macrumors 604


    Jun 10, 2006
    I see no reason why it wouldn't work. Check this: World Computing/1333D3Z3M128/
    They're 1333mHz

    My question is what can a 6,1 do that a 5,1 can't? I use mine for music (mainly video) production and I have 2 UAD Octos in there, 48GB RAM, and the 2.93GHz 12 core. My question is what does the 6,1 offer? The 5,1 can go up to 96GB RAM I believe, also 1333mHz. The CPU in the 6,1 is not much better. It is somewhat faster for single core tasks but for multi core my 12 core is only outperformed by the 12 core 6,1 model; the lesser core ones are not capable of crunching as much data as quickly. I'm not sure how important the video card is to you either, but I put in a R9 280X and this thing performs very nicely (they now have Titan X's and GTX 980's that are wicked fast).

    It sounds like budget isn't an issue, so you're looking at a little under 10 grand to get a 6,1 that is decently faster than an upgraded 5,1. A 6 core Xeon 3.46GHz upgrade can be had a $200-300 for one, or $500-600 for a pair. I guess my point is if you can't wait for a 7,1 you are kind of wasting money to upgrade full price to a 2 year old 6,1 which contains technology that is 3 years old. I added USB 3 to mine, and while it doesn't have Thunderbolt, I'm not sure it is worth buying outdated tech for at this present moment. (Thunderbolt 3 will almost certainly be included in the next MP).
  3. ActionableMango macrumors G3


    Sep 21, 2010
    I cannot say for sure unless you link to the exact RAM you'll buy, but I suspect that the DIMMs will probably be quad-ranked and registered.

    Quad ranked ram will run the whole bank of memory slower than dual-ranked DIMMs would, but you've already noted that. Registered (buffered) RAM cannot be mixed with unbuffered RAM, but that won't be a problem either since you are populating all slots.

    I can't really think of anything else, other than it's horrendously expensive and I'm a little bit envious. :rolleyes:
  4. Gordon Shamway thread starter macrumors newbie

    Nov 20, 2015
    Hi , thank you both for your replies !

    I'm replacing my current setup because I need a (powerful) rig that I can move between locations quick and easy. The nMP with lots of RAM in combination with Blackmagic's Multidock would be perfect for me. Nevertheless , thank you for your suggestions. Much appreciated.

    So far I only found the 128GB RAM Kit by Transcend ( ) and the one by OWC ( World Computing/1333D3Z3M128/ ) .

    I just want to make sure that I don't run into any issues with 128GB RAM on a nMP , because although these RAM Kits are out there Apple seems to have a reason why they don't mention this option in the Memory specifications:

  5. tuxon86 macrumors 65816

    May 22, 2012
    Memory specification are based on what was available when the machine was released. Manufacturer rarely update them when something new comes along.
  6. Gordon Shamway thread starter macrumors newbie

    Nov 20, 2015
    Ah , okay . Thanks !!
  7. mac666er macrumors regular

    Feb 7, 2008
    San Francisco, CA
    1.png I have one with that much memory.

    NO Issues.

    Let me repeat that.

    ZERO Issues.

    With memory, usually two things happen: It just works, or it doesn't. The worst thing that has happened to me with a mac and memory is having one module being dead. The mac didn't load the bank (two modules). But it did run.
  8. Gordon Shamway thread starter macrumors newbie

    Nov 20, 2015
    Hey , thanks for your reply and the info !
    Good to know that it works. ( I assume you use the OWC RAM Kit ?)
  9. mac666er macrumors regular

    Feb 7, 2008
    San Francisco, CA
    Yes, bought in July 2014. Even easier to install than previous Mac Pros.

    No issues under OS X or Windows.
  10. Gordon Shamway thread starter macrumors newbie

    Nov 20, 2015
    Thanks again !!!
  11. mikeboss macrumors 65816


    Aug 13, 2009
    the memory running at 800 MHz instead of 1866 MHz would be an issue for me...
  12. mac666er, Nov 23, 2015
    Last edited: Nov 23, 2015

    mac666er macrumors regular

    Feb 7, 2008
    San Francisco, CA

    Let me put this into perspective:

    When compiling code, analysing data sets, or ray tracing, running the memory at 800 MHz DOES NOT mean it will take twice as long...

    It does mean it takes almost twice as long to write to or read from memory. 800MHz does it at a peak of 6.2 GB/s (Peak transfer rate in the link). 1866MHz would do it at 14 GB/s. But at 128 GB of capacity, it means you use all of your memory in either 21 seconds, or 9. That assumes flawless execution and no overhead.


    I wished that speeding up memory by a factor of 2 would improve my workflow by 2 as well. This will never be the case, and I am having a hard time trying to think of an application (as in a job, rather than program) that will benefit outright like that.

    The greatest benefit was the memory capacity, more than the memory speed. I do statistical analysis, use several raytracing programs and use Xcode as well. The largest benefit is having multiple applications open that usually require at least 16 GB of RAM. With 128 Gb of RAM it means just 7 such programs (+ the OS) can be opened. Most of the time I am waiting for the CPU to finish tasks.

    Using Video Cards for computing doesn't really help me as the most memory they come with is 12 GB and they cost 5 thousand dollars :

    If I wanted to have 128 Gb of VideoRAM I would have to pay through the nose as I would need at least 10 (granted, they come with a processor as well, but still)... but even then, they would be split in 10 cards... and that assumes my software is ready to go to use the cards.

    Overall, RAM running at 800MHz is half the speed or a third the speed that the module was designed to run at. Yes, this means it is not being really pushed to its specs. But I would be interested in looking at a use case where this factor changed the time to do a project from 1 week to three days.
  13. bax2003 macrumors 6502a


    Dec 25, 2011
    Yes, easier to get to the DIMMs but it also easier to brake those moving rails. You can not to something like that with 2006/2008 risers or 2009/2010 cpu boards laying flat on the table.....

  14. ActionableMango, Nov 23, 2015
    Last edited: Nov 23, 2015

    ActionableMango macrumors G3


    Sep 21, 2010
    You make a lot of great points.

    I'd also like to add that, even if the maximum memory configuration is a little bit slower, it's not going to be anywhere near as slow as paging out due to running out of RAM.
  15. AidenShaw macrumors P6


    Feb 8, 2003
    The Peninsula
    Not sure about the tools, but sometimes memory reports are off by a factor of 2. A "clock rate" vs "effective data rate" issue.

    Some utilities say that my E5-1600v2 is at 931 MHz, some say 1862.

    800 MHz sounds way too low - I would be surprised if the effective data rate isn't 1600MHz.

    ps: nMP sucks. (Have to say that - some people want to believe that some of us are only here to post negative comments about the MP6,1. Don't want to disappoint them.)

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14 November 20, 2015