Upgrading iMac Ram - keep Apples Stock memory?

Discussion in 'iMac' started by EdwardWeston, Apr 11, 2019.

  1. EdwardWeston macrumors newbie

    Joined:
    Dec 25, 2018
    #1
    Hi,

    Just got a new 2019 i9 iMac 27" and also purchased the required ram (2x16gb = 32gb). I'm a photoshop and capture one user (who using the comp for everything, so email, word, safari, etc are all open while working).

    Here is my question - is it better to remove the 2x4gb ram and just have the two 16gb sticks? or have the added 8gb bonus of Apple ram? (all the sticks are matching specs in ghz). And the 32gb is the Crucial

    Crucial 32GB Kit (16GBx2) DDR4 2666 MT/s (PC4-21300) DR x8 SODIMM 260-Pin Memory - CT2K16G4SFD8266

     
  2. rugby4all macrumors newbie

    rugby4all

    Joined:
    Mar 30, 2019
    #2
    There are no compelling reasons to remove Apple installed RAM (8GB) if installing just 2 more modules, just installed the 2x16GB in the empty channels. And your iMac will be running with 40GB of RAM, which should be more than enough for your described use. Enjoy!
     
  3. rychencop macrumors 65816

    rychencop

    Joined:
    Aug 17, 2007
    Location:
    South Carolina
    #3
    yup...just install the new sticks in the empty slots. GTG
     
  4. EdwardWeston thread starter macrumors newbie

    Joined:
    Dec 25, 2018
    #4
    Excellent. I heard someone once say that it was inefficient to have the 2x4gb ram sticks in with the 2 16gb. But you know the internet, any truths?
     
  5. rychencop macrumors 65816

    rychencop

    Joined:
    Aug 17, 2007
    Location:
    South Carolina
    #5
    I don't think so as long as you keep the specs the same, the size shouldn't matter. I've had zero issues that I'm aware of.
     
  6. macduke macrumors G4

    macduke

    Joined:
    Jun 27, 2007
    Location:
    Central U.S.
    #6
    No. Should probably be the same speed, but worst case it drops them all to the slowest speed I think. Slot 0 and slot 2 are the slots Apple puts theirs into. Fill in the others. Why do they do this? Slot 0 and 2 are DIMM0 and Slot 1 and 3 are DIMM1. Slot 0 is A channel and slot 2 is B channel. Slot 1 is A channel and slot 3 is B channel. Match DIMM0 A/B channel to each other and match DIMM1 A/B channel to each other in capacity. Then you will get full speed dual channel DDR4 2666 assuming you bought the proper RAM modules. It looks like you bought the same ones I did so you will get full speed at 40GB like me. Takes about two minutes to upgrade if you do it right out of the box. No need to boot it up first.
     
  7. RemarkabLee macrumors 6502a

    Joined:
    Nov 14, 2007
    #7
    Well this is interesting... I've done exactly what the OP has done and I've noticed the following:

    Only Apple stock RAM installed slot 0 and 2, runs at 2667 (2x4 Gb sticks)
    Only Corsair DDR4 2666 SO-DIMMs installed slot 0 and 2, also runs at 2667 (2x16Gb)
    Both Apple sticks installed slot 0 and 2 and Corsair slot 1 and 3, all four drop down to 2400

    Is this a result of capacity difference or a general incompatibility with brands?
     
  8. donkuok macrumors newbie

    donkuok

    Joined:
    Apr 14, 2019
    #8
    Yes both have different CAS CL17 vs CL19. So far Crucial is the best fit to get 2666
     
  9. mrvo macrumors member

    Joined:
    Nov 16, 2018
    #9
  10. RemarkabLee, Apr 18, 2019
    Last edited: Apr 18, 2019

    RemarkabLee macrumors 6502a

    Joined:
    Nov 14, 2007
    #10
    Thanks for that.
    I was using these with 18-19-19-39
    Have ordered these as a replacement - not sure of CAS rating though.

    Anyone know the full rating of the stock Apple RAM?
     
  11. AlaskaMoose macrumors 68000

    Joined:
    Apr 26, 2008
    Location:
    Alaska
    #11
    Just had a chat with Crucial, and this is the RAM pair they recommend for the 3.1GHz iMac:
    https://www.amazon.com/Crucial-16GBx2-PC4-21300-SODIMM-260-Pin/dp/B071H38422

    Neither Crucial nor Amazon have the means for matching the RAM to the iMac at their websites, but the specs of their RAM match the Apple's recommended specs. Crucial ran out of stock at the moment, so I am buying mine from Amazon
     
  12. drewaz macrumors 6502

    Joined:
    Dec 4, 2012
    Location:
    Phoenix
    #12
    I've been using the 16GB crucial kit added to the stock Apple RAM: works fine.
     
  13. SkiHound2 macrumors regular

    Joined:
    Jul 15, 2018
    #13
    I would boot the computer before adding the ram. I had a completely dead Mini. I want to make sure things are running as the computer comes out of the box. I opted for a new iMac. Had I stuck ram in and the computer would've been dead I'd have wondered if I did something wrong. The upgrade is easy.
     
  14. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #14
    Which Crucial should I take if I just want 16GB (2x8GB). People is just linking to 32.

    Is it Non ECC or ECC I need to look for?
    --- Post Merged, Apr 18, 2019 ---
    Also does OWC sell in the UK? I have found resellers bt not sure they offer the same guarantee
     
  15. marzfreerider macrumors member

    Joined:
    Jun 13, 2014
    Location:
    Canada
    #15
    You want Non-ECC, You can get the 16GB (2x8) version of it if you like, just make sure the specs match what you want. Crucial has said that it is compatible. Not sure about OWC there.
     
  16. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #16
    I would like Crucial, it's the one I have on my 2011. I know I need the PC4 21300, 2666, SODIMM 260 pin. The other doubt I have is, it has to be dual rank right? what is dual rank and single rank? IS that what allows the RAM to work in dual channel?

    I can't seem to find crucials 16 GB kit of 2x8GB. While I Can afford the 32 GB kit, it would really be overkill for me. I currently have 12 GB on my 2011, and this one will have 24GB.

    Also, do you get the same guarantee from Amazon as form their website?
    --- Post Merged, Apr 19, 2019 ---
    I have just been in the crual service chant and was told the following.

    "I'm afraid that we still haven't received any update on when compatible upgrades will be added in website. However, the appropriate department are working to release compatible modules as soon as possible."

    How can it be that they say there is no compatible modules? Are we sure those mentioned above work? I Know they have same clock speed and such but...

    https://www.amazon.co.uk/Crucial-CT...38692&s=computers&sr=1-2-fkmrnull-spons&psc=1
     
  17. curmudgeonette macrumors 6502a

    Joined:
    Jan 28, 2016
    Location:
    California
    #17
    Dual rank has nothing to do with dual channel.

    Dual rank describes how the module is configured. At a given technology level, there's a maximum possible module capacity. However, there's usually space to have a second rank of chips that double the module capacity. Thus, the highest capacity module will be dual rank. As tech improves, it'll be superseded by a single rank module.

    In 2017, the standard RAM was 8gbit. You could use eight 1gbit*8 chips to make an 8GByte single rank module. With sixteen chips, you could max out to a 16GB dual rank module. In the other direction, you could use four 512mbit*16 chips for a 4GB module, or two 256mbit*32 chips for a 2GB module.

    A simple consumer observation is that dual rank modules are likely double sided, and single ranks are single sided.

    Also, dual rank modules are more likely to work with older CPUs.
     
  18. AlaskaMoose, Apr 19, 2019
    Last edited: Apr 19, 2019

    AlaskaMoose macrumors 68000

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    Apr 26, 2008
    Location:
    Alaska
    #18
    Your questions can be answered during a chat at Crucial. That is what I did, and it was explained to me that the RAM sticks I wanted for my 2019 27" 5K iMac (the 3.1GHz one) matched the Apple RAM's specifications. Before they can guarantee that the RAM are 100% compatible, they have to test it on an iMac. As you probably noticed, the Crucial RAM is being sold for several computers other than the 2019 iMac.

    My iMac is on its way from Apple, and I did order the 32GB ram sticks from Amazon because it is about $30.00 cheaper then OWC ("macsales.com"). But OWC guarantees their RAM. Some of us who are buying the "not guaranteed" Crucial RAM are just matching the Apple's specifications for the 2019 iMac.

    OWC:
    https://eshop.macsales.com/shop/memory/imac-2019-27-inch
     
  19. drewaz macrumors 6502

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    Dec 4, 2012
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    Phoenix
    #19
  20. upthetoffees macrumors regular

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    Jun 4, 2012
    #20
    --- Post Merged, Apr 20, 2019 ---
    I just bought ram you highlighted from amazon and it says notebook on the package that holds the ram, normal?
     
  21. brianmonty macrumors newbie

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    Mar 26, 2008
  22. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #22
    Ok, so thinking about the 2019 iMac, what would be better dual rank or single rank
    --- Post Merged, Apr 20, 2019 ---
    That one I have already seen, but it is single ranked, while those getting the 32GB pack are getting dual ranked
     
  23. Glockworkorange macrumors 68000

    Glockworkorange

    Joined:
    Feb 10, 2015
    Location:
    Chicago, Illinois
    #23
    Good advice.

    I kept the 8, added 16 to it from OWC and will probably never need to add RAM again for my uses.

    If you lost or ditch or sell the RAM and you need to bring the machine in for an issue, Apple is going to ask where the original RAM is, as some problems are caused by RAM.

    That happened to me with a 2014 5K.
     
  24. curmudgeonette macrumors 6502a

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    Jan 28, 2016
    Location:
    California
    #24
    You don't get to choose single or dual rank. You pick your capacity and that will determine whether it is single or dual.
     
  25. kaintxu macrumors regular

    Joined:
    Jul 9, 2018
    #25
    Thank makes sense, the 8GB sticks are single rank, while the 16GB stick are dual rank as they are twice.

    I will be then get the following.

    https://www.amazon.co.uk/gp/product...tle_o03_s00?tag=skim1x150840-21&ie=UTF8&psc=1

    is RAM prices something that change a lot, as in can I Expect it to go down in price soon, or the stay quite similar.
    --- Post Merged, Apr 20, 2019 ---
    So about the price.

    I've found the following:

    https://uk.camelcamelcamel.com/Crucial-CT2K8G4SFS8266-Memory-PC4-21300-260-Pin/product/B071KP8CGG

    in just 3 months, RAM has come down £30 and halved in the last year. Im not a rush of getting the aditional 16GB (it could wait a month or 2) so how realistic is it that it could go down in that period of time?
     

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28 April 11, 2019