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Is this the correct RAM for the new 2019 iMac?

patearrings

macrumors regular
Original poster
Mar 4, 2009
130
62
Just ordered my new imac yesterday, and thanks to all the helpful posts on here with my decision.

In the end i went for the top spec 27" i5 9600k with radeon 48 (upgrade) and 512 SSD.

I had a quick question about the ram. It only comes with 8gb and so i have ordered this. I just wanted to double check with you guys as i still have time to cancel the order, is this the correct ram?

https://www.amazon.co.uk/dp/B071KNKBQ1/ref=pe_3187911_185740111_TE_item?th=1

Thanks
 
Last edited:

fwh32720

macrumors newbie
Mar 25, 2012
14
1
I think it is best to purchase RAM in pairs. Someone please correct me if I am wrong.
 

patearrings

macrumors regular
Original poster
Mar 4, 2009
130
62
I think it is best to purchase RAM in pairs. Someone please correct me if I am wrong.
i was going to buy another 8gb stick in due course to pair with that one. so i will have 2 x 4gb (apple) and 2x 8gb (crucial) taking me to 24gb.

But i need to know if it's the correct RAM?
 

patearrings

macrumors regular
Original poster
Mar 4, 2009
130
62
Isn’t it ok to just buy this stick and then buy the same stick again at a later date?
 

patearrings

macrumors regular
Original poster
Mar 4, 2009
130
62
Right, i see my mistake, so i need to buy a kit of 2 x8gb

When i look at those though, they are listed as single rank or dual rank? Can someone tell me what the difference is please?

I use crucial ram and usually use their scanner, but since i don't have the mac yet, and it also cant be selected from the drop down menu of models, im kinda stuck!

Any help would be great :)
 

curmudgeonette

macrumors 6502a
Jan 28, 2016
571
452
California
When i look at those though, they are listed as single rank or dual rank? Can someone tell me what the difference is please?

Dual rank is essentially two memory sets on one DIMM. This is a standard way to increase the capacity - the CPU has built in support for doing this.

Other names for dual rank: Double sided. Low density.

As memory sizes grow, initially dual rank is the only way to reach the maximum. Eventually, higher density chips are developed and a single rank module is possible. In 2017, the only way to max out an iMac was with dual rank modules. Today, you can probably get the same capacity with single rank modules. The 2019's once again (probably) can only be maxed with dual rank modules - but the max is now double.

Dual rank is more compatible with older CPUs. Single rank will be more compatible with future CPUs that drop support for older low density chips.
 

patearrings

macrumors regular
Original poster
Mar 4, 2009
130
62
Ok, i spoke to Crucial ram here in the UK this morning and they say they dont yet know what ram will be compatible for the new 2019 imac!

Apple's site lists it as:

8GB (two 4GB) of 2666MHz DDR4 memory; four SO-DIMM slots, user accessible

Which Crucial actually stock, but of course i dont know the CAS latency etc.

Is there anyone out there with a 27" imac with the ddr4 2666mhz ram that would be willing to run the crucial ram scanner for me please? As although they say they don't know whats comaptible, i am almost sure the ram they stock will be the correct spec.

Here is the scanner tool:

https://uk.crucial.com/

Just click on "Scan Computer"

Any help is greatly appreciated.
 
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rugby4all

macrumors newbie
Mar 30, 2019
15
7
https://www.bhphotovideo.com/c/product/1333839-REG/crucial_ct2k16g4sfd8266_32gb_kit_16gbx2_ddr4.html
https://eshop.macsales.com/item/OWC/2666DDR4S32P/
Is there a difference between the two? The one at B&H is cheaper. They look the same, but maybe i am wrong?
They do look the same and both are compatible with the 2018 Mac Mini according to reviews, so should be compatible with iMac.
In addition B&H is a good company so if they don’t work (which they should), you should be able to return them without any problem.
 
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