RAM upgrades: theoretical advantages to using or ditching stock modules

Discussion in 'iMac' started by exi, Jun 21, 2017.

  1. exi, Jun 21, 2017
    Last edited: Jun 21, 2017

    exi macrumors 6502

    Oct 16, 2012
    iMac coming this week with 8GB, i7, 580, SSD.

    Have a pair of Kingston HyperX modules for the system, 2x16 GB.

    Just curious what the MacRumors take on the stock modules is like these days. Better to leave them in place and install mine around them, resulting in mismatched pairs to 40 GB with different timings (but all DDR4/2400), or take Apple's RAM out and install my own, resulting in a single matched pair to 32 GB?

    My feeling is the latter but unsure how much it actually matters in day-to-day (routine office use, gaming in Boot Camp) function.
  2. ZMacintosh macrumors 65816


    Nov 13, 2008
    Mac OS side shouldn't make a difference, as the RAM generally will clock to the lowest modules. Windows, I'm not 100% sure on.

    I don't think either option would have much of an affect on performance and should be either way, but for consistency sake there shouldn't be an issue ditching stock RAM
  3. trsblader macrumors 6502

    May 20, 2011
    Doesn't matter, stick both sets in and be done with it. If you really want to dig through hundreds if not thousands of opinions in the dozen or so threads on this topic in the past month feel free, but theres plenty of people already doing that and posting nothing but good results.
  4. phpmaven macrumors 68040


    Jun 12, 2009
    San Clemente, CA USA
    Well... It doesn't matter unless you don't care if the clock speed of your HyperX modules slow down to the speed of the pre-installed ones.
  5. exi thread starter macrumors 6502

    Oct 16, 2012
    Just to clarify, my modules are DDR4 2400 just as those preinstalled. I'm actually just nitpicking the premise of mix/match chips (although at a floor of 32 GB, I can't imagine I'll be using anything at this point in time to consume that much RAM) and the actual timings/latencies -- something I'm rusty on these days as I only tinkered a bit with manually adjusting these things back in the DDR/DDR2 days when I built my own machines.

    More for my own education, I suppose.
  6. Traverse macrumors 604


    Mar 11, 2013
    (Not to derail the OPs thread, but)

    I hear arguments for both.

    So, my Mac came with 2 8GB sticks. If I buy 2 4GB sticks from Crucial can I just put them in the empty slots or do I need to rearrange them?
  7. Glockworkorange macrumors 65816


    Feb 10, 2015
    Chicago, Illinois
    I have mismatched RAM (24, 8 with the iMac and 16 from OWC).

    Zero issues.
    --- Post Merged, Jun 21, 2017 ---
    I just threw mine in the empty slots.
  8. mmomega macrumors demi-god


    Dec 30, 2009
    DFW, TX
    One sure fire way to find out.
    Mix match them. Use the Mac.
    If problem arise, remove the mismatch, use the Mac.

    Troubleshooting will give you way more experience than opinions. Especially on a topic that won't very well damage anything when installed properly.
  9. fcracer macrumors newbie


    Jun 15, 2017
    The HyperX ram is CL14 whereas the factory ram is CL17. The mismatch will result in the computer slowing the ram speed down to 2133MHz. Adding the faster CL14 ram will still result in improved performance but nowhere near what you'd get with only two of the CL14 sticks or four of the CL14 sticks. Please see my post which has comparison numbers from Geekbench.

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