Will This Mem Work & Max Mem? (4,1)

Discussion in 'MacBook Pro' started by Syndacate, Dec 8, 2011.

  1. Syndacate macrumors regular

    Mar 16, 2008

    I'm looking to buy my g/f some memory for Christmas.

    I'm 90% sure she has a MBP 4,1 (either a 4,1 or a 4,2, I don't have the computer in front of me).

    I was looking at buying this memory:

    This will work, correct?

    Also, would doing 6GB with this combo be feasible? :

    Reason I ask is I remember somebody saying at one point that 4GB was the 'cap' - but it used 6GB fine, and 8GB made it laggy. Forgot where I heard that, though, might just be a myth. Would 6GB cause speed problems due to it being dual channel with a 4 & 2?

    She keeps every ****ing application possible open at the same time, hers only has 2GB, and it's nowhere near enough, so it's paging like a bitch and making the computer slow as all hell once she's used it for about a day.

  2. snaky69 macrumors 603

    Mar 14, 2008
    The 4,1 will take a max of 6GB, your information is correct.

    I believe macsales.com has a 6Gb kit you can buy all at once.
  3. Syndacate thread starter macrumors regular

    Mar 16, 2008

    Yeah, I found this there.

    Only problem is it's 50% more expensive than matched Patriot memory 4 & 2 bought separately, and I've never heard of OWC RAM.

    In any event, will she run into speed issues because the RAM isn't matched if you put a 4x1 and a 2x1 in there (DDR2 is dual channel)?
  4. snaky69 macrumors 603

    Mar 14, 2008
    No speed problems whatsoever will arise, I don't see why there would be any. OWC is as reputable a brand as any as far as RAM goes. You lose the dual channel but you have 2gb's more before you start using virtual memory, so the point(to me) is moot.

    Just match the specs of said RAM from whatever brand you prefer on another site.
  5. Syndacate thread starter macrumors regular

    Mar 16, 2008
    Yeah, I guess it's like going from a 250GB drive at 5400 RPM to a 100GB drive at 7200 RPM, or a 500GB drive at 5400 RPM.

    Losing the dual channels means you have a higher access latency. On the flipside, as slow as memory access is on an architectural level, it's typically very hard to notice as a user.. I hate trade-offs :p.

    Now I just got to decide if all her crap can fit on 4GB o_O.

    Thx :)
  6. m85476585 macrumors 65816

    Feb 26, 2008
    Modern chipsets can do asymmetric dual channel. In this case the first 4gb is dual channel and the remaining 2gb runs as single channel, or something like that. It's difficult to find details, and it's been a long time since I've looked into it. You won't notice a difference in speed, though.

    I've been running 6gb in my MBP4,1 for about two years now with no issues at all. There's a huge thread about it somewhere that gets dragged up every once in a while.
  7. Syndacate thread starter macrumors regular

    Mar 16, 2008
    Yeah, if it's running in asymmetric dual channel mode then it uses them both independently, so it won't be running the first 2GB of the second stick interleaved or anything, they'll be completely separate, and slower.

    Yeah, I have to agree with you that it's unlikely the difference will be noticeable, as the only thing that will take a hit is large memory reads, and she doesn't do any media editing anymore. Maybe Firefox, though, when she gets her 10,000 tabs open :p).

    I'll probably go with the 6GB.
  8. m85476585 macrumors 65816

    Feb 26, 2008
    My point is that it does in fact interleave the first 4gb. Here's what the Intel PM965 (chipset used in Santa Rosa laptops before ours) says about it:


    The chipset in the 4,1 might be different, but I couldn't figure out which one it is. If it's Intel it's a given that it will also support Flex Memory. If it's Nvidia, I think they have their own implementation of Flex Memory/asymmetric dual channel, but they don't publicize the details (full datasheets are only available for hardware manufacturers).
  9. Syndacate thread starter macrumors regular

    Mar 16, 2008
    Ah, I didn't know about this Flex tech. Gotcha, thank you.

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