8GB RAM may not be interleaved

Discussion in 'MacBook Pro' started by belvdr, Jun 15, 2009.

  1. belvdr macrumors 603

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    #1
    According to iPod Touch Hacks, an Apple Genius is stating that if you upgrade one of the new machines to 8GB, the RAM will not be interleaved, causing a slowdown to your system.

    Reading through the comments, some say it's not true, but I don't know of a way to say this is accurate or not. I've had other systems that would do this as well, but don't know the accuracy of this for these models.

    I believe folks here may want to research this some more if you plan on upgrading.
     
  2. MacModMachine macrumors 68020

    MacModMachine

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    #2
    loosing interleaved mode is very little loss, 10% maybe
     
  3. iLog.Genius macrumors 601

    iLog.Genius

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    #3
    Yeah. I guess it's like having 6GB without dual channel support. But I think that dude it's talking out of his ass. I would "kind of" understand if it was the first unibody models but the new ones DO support 8GB out of the box and there isn't "Apple" RAM. RAM is RAM.
     
  4. speed3 macrumors newbie

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    #4
    To repeat my comments on the ipodtouchhacks site, it's not clear that the Apple Genius meant to say that only Apple-installed RAM would be interleaved. After reading the story carefully, he could have meant that, for some unspecified technical reason, any 8 GB RAM upgrade would suffer from the same problem (e.g., perhaps because 8 GB of notebook RAM is still a rather new or cutting-edge thing).
     
  5. belvdr thread starter macrumors 603

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    #5
    I don't think you can be that general with it. If you have a requirement (not a want) for 8GB of RAM, it can be a huge benefit.

    Like the poster above, it may be the supplier for Apple's RAM or it could be something on the board that disables interleaving when 4GB sticks are installed. At this point, it's just a rumor, but it's worth someone checking into if they are preparing to upgrade.
     
  6. MacModMachine macrumors 68020

    MacModMachine

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    #6
    not really, i have benchmarked between interleaved 4gb on a desktop and 1 4gb stick, there were little advantages to it.
     
  7. belvdr thread starter macrumors 603

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    #7
    Hmm, I wonder if non-interleaved 2 sticks would be any different than 1 stick. I had a system with dual channel DDR and it ran much slower when I disabled dual channel using the same sticks.
     
  8. maflynn Moderator

    maflynn

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    #8
    I think over-all performance will be improved with the 8gb, even if its not interleaved. The increased memory benefit offsets for the most part any possible performance penalty of not having the ram interleaved. Until I see some hard evidence this is the case and some specific benchmarks, I'd not really get too worked up over this.
     
  9. belvdr thread starter macrumors 603

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    #9
    That depends on what you're doing. If the tasks you are doing only consume 2GB of RAM, and you have 4GB, then upgrading to 8GB will not help at all. It will be interesting to see how this pans out. Given Apple took away SATA-II on some models, it wouldn't surprise me to hear this is true.
     
  10. maflynn Moderator

    maflynn

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    #10
    Agreed, and the same thing could be said with 6gb, and even 2gb. It depends on your usage. Since this thread is about 8gb and possible performance penalty, its assumed that people who upgrade to 8gb, actually need 8gb. For those folks, the performance increase of more memory should offset any possible performance penalty for not interleaving the ram.
     
  11. MacModMachine macrumors 68020

    MacModMachine

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  12. belvdr thread starter macrumors 603

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    #12
    Just another reason not to trust Wikipedia as gospel. If you read the Tom's Hardware article Wikipedia references:

    Someone needing 8GB of RAM is hardly using regular applications.

    EDIT: I should add they were only referencing dual channel.
     
  13. Dwalls90 macrumors 601

    Dwalls90

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    #13
    Interleaved? Is that the same as dual channel?
     
  14. belvdr thread starter macrumors 603

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    #14
    I know dual channel is interleaving, but not all interleaving is dual channel. I've seen reference to triple channel now.
     
  15. MacModMachine macrumors 68020

    MacModMachine

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    #15
    look at it as a raid0 on 2 sticks and now 3 sticks of ram

    interleaved and dual channel are the same
     

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