Can 1866 MHz RAM damage your iMac?

Discussion in 'iMac' started by Fried Potato, Jan 10, 2015.

  1. Fried Potato macrumors member

    Fried Potato

    Joined:
    Jan 10, 2015
    #1
    Hi guys,

    I've ordered a Retina iMac which is estimated to arrive early next week. I chose the 8GB option as I don't want to pay the price Apple asks for their 32GB option. Although, I am going to buy seperate 32 GB RAM sticks, but I do have one question: I read a post here about 1866 MHz RAM sticks working with the new Retina iMac, although I can't seem to find the post any longer. If I'd go with 1866 MHz RAM, would that damage my computer in anyway? Do they get hotter than normal 1600 MHz RAM? I chose the high end Retina iMac (everything maxed except RAM) and I've heard that the GPU does reach high temperatures. I don't want to further increase the temperature.

    If the 1866 MHz RAM doesn't do any harm; could you recommend me any specific 1886 MHz RAM? Otherwise, which 1600 MHz would you recommend?
     
  2. applebutter macrumors newbie

    Joined:
    Oct 30, 2014
    #2
    I doubt that 1866 MHz RAM would hurt your rImac, if anything it would most likely drop the speed to 1600 MHz. I wouldn't worry about it...
     
  3. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #3
    http://forums.macrumors.com/showthread.php?t=1815203

    Not only is it fine to use 1866 MHz RAM, it will also result in better performance.
     
  4. Fried Potato thread starter macrumors member

    Fried Potato

    Joined:
    Jan 10, 2015
    #4
    Are you sure that 1866 MHz RAM doesn't generate more heat compared to the stock 1666 MHz RAM? In such case, should I go with the 1866 MHz Crucial RAM mentioned in the thread posted above? It seems like they're the only available 1866 MHz SODIMM RAM, at least after looking around some web stores.
     
  5. phpmaven macrumors 68040

    phpmaven

    Joined:
    Jun 12, 2009
    Location:
    San Clemente, CA USA
    #5
    There should be no added heat. These are the ones that I put in my 5K and they are running at 1867Mhz.
    http://www.amazon.com/gp/product/B00KQCOT3Q

    They have worked flawlessly so far, but you are not going to notice any real world difference. I just figure I want to eek out every last bit of possible performance, so I always try to get the best performing components, but it's debatable whether it's worth the extra money, although it's not that much.
     
  6. Fried Potato, Jan 11, 2015
    Last edited: Jan 11, 2015

    Fried Potato thread starter macrumors member

    Fried Potato

    Joined:
    Jan 10, 2015
    #6
    Same here. I always have to go with the top perfoming specifications, even though I'm aware that I won't feel the extra power. :)

    Which one of these two 1866 MHz options would you guys recommend?

    First option: Crucial Ballistix Sport 1866 MHz (same RAM tested in the thread mentioned a couple of posts above).
    Second option: Kingston HyperX Impact Black Series 1866 MHz (mentioned in the post just above this one).

    Would Crucial be the better option? Just a feeling I have, seems like I've heard more about Crucial than Kingston. Also, when checking both these RAM's, they state in the specifications that the voltage is 1.35 / 1.5. Does that mean that they're compatible with both voltage options? As I've mentioned, I don't want these RAM sticks to generate more heat, so I'd like them to hold to the Mac's stock RAM voltage.

    EDIT: It seems like the Kingston RAM isn't available here in Sweden (actually, the 4 GB sticks are available, but that isn't what I'm out after). So I guess that I'll go with the Crucial RAM. Just to double check, this is the correct RAM, right? The link's in Swedish, but I guess you'll be able to confirm if it's the right one.
     
  7. Shpenza macrumors regular

    Joined:
    Mar 12, 2010
    Location:
    Barcelona
    #7
    I would go with the kingston (I also am thinking on upgrading), as they specify that its compatible with the iMac 5K on their site, I dont see that on Crucial's site, therefor its a bit more "risky" to buy them.

    http://www.kingston.com/en/memory/search?DeviceType=2&Mfr=APP&Line=iMac&Model=90781
     
  8. lssmit02 macrumors 6502

    Joined:
    Mar 25, 2004
    #8
    Using 2133mhz ram

    Found some G.Skill Ripjaws for my RiMac selling for just a little more than the 1866 Crucials. System reports they are running at full speed. No issues with heat as far as I can tell. Everything is running great.
     
  9. Fried Potato thread starter macrumors member

    Fried Potato

    Joined:
    Jan 10, 2015
    #9
    As I stated in my edit above: the 8GB sticks from Kingston aren't available here in Sweden. The Kingston sticks (incorrectly) linked above are 4 GB.

    Although, I just saw these RAM sticks from Kingston. They cost less than the Crucials and they have a higher frequency. Should I go with these instead?
     
  10. Alesc macrumors 6502

    Alesc

    Joined:
    Nov 11, 2014
    Location:
    France
    #10
    On your link it is 2x4 Go. ;)
    I would go with Crucial: you can find topics here with Retina iMacs working great with the Crucial 1866 RAM. Crucial sell really good products.
    The 1866MHz sticks are not recommanded for Macs on their website because they have dedicated sticks for Macs. And the 1866 or CAS9 sticks can cause problem if you mix them with Apple stock RAM (the four modules will run slower to adapt to the lower CAS).
    But if you don't mix your new modules with Apple stock RAM, go for 32 GB of 1866 MHz Crucial RAM. If you wan't to mix the stock 8GB with 2x8GB new sticks, order the Crucial Mac RAM (1600 MHz). :)
     
  11. Fried Potato thread starter macrumors member

    Fried Potato

    Joined:
    Jan 10, 2015
    #11
    I just ordered the Crucial 1866 MHz RAM sticks (32 GB). :)

    By the way, should I just pop the sticks into to the back of the iMac and it'll be ready to go? Should I run any kind of memory diagnostics to ensure that the RAM sticks are okay?
     
  12. Alesc macrumors 6502

    Alesc

    Joined:
    Nov 11, 2014
    Location:
    France
    #12
    Plug and play! ;)
    If the memory is wrong, the machine won't boot or you will have a lot of Kernel Panics.

    But it will be all right ;)
     
  13. roadkill401 macrumors 6502

    roadkill401

    Joined:
    Jan 11, 2015
    #13
    I don't know if I'd say plug and play.

    Any and every bit of memory needs to be extensively tested as I have found the failure ratio on most memory now is excessively hight. They sell it for cheep and to do that I am guessing the production QC is down or non existent. it costs more for them to test the memory than it does to offload that to the consumer and just deal with RMA's for the defective ones.

    I would look into making a memtest86 usb stick and leave it to run over night.

    that said, I am told that the only correct way to test the chips is to insert them one at a time and test each of them individually. I have had memory that was very unstable but passed memtest every time when done as a batch. This was on a PC but lets face it, they are essentially all using intel chips so the same holds true. As soon as I tested each dimm individually, I found that 3 out of the 4 I had bought were bad. Got them RMA exchanged no problem and all was well. But there was 5 months that I could not explain why my computer would randomly crash when booting from a cold state, but mostly work fine if just left on, and not left to sleep for more than 24 hours.

    BTW: that is why Apple memory is so expensive. it is actually tested before it is installed. Doesn't make it any better, but apple QC is far better than most and you pay for that.
     
  14. Alesc macrumors 6502

    Alesc

    Joined:
    Nov 11, 2014
    Location:
    France
    #14
    In the past ten years, I never had a defectuous DIMM... And manufacturers like Crucial also test their DIMM, and their after sale service is excellent. No need to worry in buying RAM at Crucial or other big manufacturers today. :)
     
  15. Chippy99, Jan 13, 2015
    Last edited: Jan 13, 2015

    Chippy99 macrumors 6502a

    Joined:
    Apr 28, 2012
    #15
    Can it damage your Mac?

    From a hardware perspective, almost certainly not.

    But software-wise, maybe, perhaps. Unlikely but perhaps.

    What is indisputable is that 1866MHz is out of spec. The Intel CPU and Apple main board are not specified to work properly at that speed.

    Running 8 or 16GB of ram this is unlikely to be an issue. But running 32GB loads the memory controller more and makes flawless operation more difficult. Voltages and timings are more difficult to maintain under heavier loading. This is even more relevant when speeds are higher and timings more critical. This can result in memory read errors and kernel panics. These in turn can result in disk corruption and data loss.

    These things are not necessarily "likely", but it's not just theoretical and only a remote possibility either. Kernel panics with systems with 32GB of third party ram are relatively common and with 1866 ram will be even more likely. They will also generate more heat than 1600MHz ram, but that's probably irrelevant in the scheme of things - a few watts more at most.
     

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