Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

tomtendo

Suspended
Original poster
Aug 29, 2009
813
933
Florida
What's the best RAM that I should buy (From Amazon) that is compatible with my iMac 27 2013 model.
 
Sweet thanks! Curious tho... What 32GB ram works too? This only goes up to 16gb. or do you just buy 2 of these?

Yep. The 27" iMac has four RAM slots. By default, two of them are filled with 4GB sticks, and two of them are empty. You could buy the 16GB package (which has two 8GB sticks) and place them in the empty slots for a total of 24GB of RAM, or buy two packages of this and replace the factory RAM for a total of 32GB.

Fun note, the Factory RAM I pulled from my 2013 iMac was made by Micron, the same company that owns Crucial and makes it's memory modules.
 
http://www.amazon.com/gp/product/B00DSGLMSM/ref=wms_ohs_product?ie=UTF8&psc=1

I have this in my iMac (32GB) and has been since Day 1. No kernal panics, not one problem and yes it is a 16GB kit so you just purchase 2 sets to get to 32GB.

That's really nice RAM but I have to assume one would be paying the extra money in order to get the performance boost of the 1866MHz clock speed. If so, be aware that using it in combination with slower RAM will cause it to clock down to match.

The Crucial CT2C8G3S160BM is quite speedy and it's been rock solid for me for the past 4 months in combination with 16GB of stock Apple Elpida.
 
As an Amazon Associate, MacRumors earns a commission from qualifying purchases made through links in this post.
That's really nice RAM but I have to assume one would be paying the extra money in order to get the performance boost of the 1866MHz clock speed. If so, be aware that using it in combination with slower RAM will cause it to clock down to match.

The Crucial CT2C8G3S160BM is quite speedy and it's been rock solid for me for the past 4 months in combination with 16GB of stock Apple Elpida.

This is possible, my experience is that all of the RAM will go to the slowest speed of the slowest RAM so it would effectively down clock the 1866MHz to 1600MHz if installed along with stock RAM, which is why I just installed only the 1866 RAM in the iMac.
I happen to be in different circumstances and I installed my stock RAM into my wife's 2012 iMac i7 so she got a free bump to 16GB.

If she's happy, then I can be happy :)
 
Does the iMac motherboard even support 1866Mhz? I was under the impression that would be the bottleneck keeping speeds down to 1600Mhz.
 
Does the iMac motherboard even support 1866Mhz? I was under the impression that would be the bottleneck keeping speeds down to 1600Mhz.

The iMac shows it running as 1867MHz in each slot as well as GeekBench showing the RAM at 1867 with a slight speed performance and bench testing boost.

On a similar note.

I have 16GB of 1866MHz RAM installed in my Mac Mini and it is showing under everything as 1600MHz and shows that speed increase isn't there when bench tested whereas the iMac does.

Now, can I tell the difference? Probably not.
I custom ordered this machine (for the VESA mount and 256 flash) and removed the stock Apple RAM and replaced with the 1867 before I even connected the power cord so it has been this way since 1st boot.

I'm not saying this is the way for everyone to go but that it is an option. Just use 1.35v RAM not 1.5v since this is what the iMac uses and you won't potentially run into overheating issues.

Also as SaSaSushi stated, you wouldn't want to mix RAM speeds. Pick 1 speed and use that or your 1866 RAM will just drop to 1600 if it is installed along side stock 1600MHz RAM.
 

Attachments

  • Screen Shot 2014-07-08 at 11.30.50 AM.png
    Screen Shot 2014-07-08 at 11.30.50 AM.png
    1,021.2 KB · Views: 265
Last edited:
mmomega: Huh, that's pretty cool. :)

Not cool enough for me to replace the 32MB of Crucial 1600MHz ram I just bought, but pretty cool nonetheless.

Thermonuclear: That's where I'd gotten my impression too, but Apple has a history of being a little conservative about the supported configurations, compared to what's actually possible. On the flip side, users can be a little delusional about the benefits of the parts they use, so I tend to be skeptical until evidence is provided :D
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.