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spinstorm

macrumors 68000
Original poster
Sep 14, 2007
1,603
143
I want to add my own RAM to the 27" iMac I ordered today.

Does anyone know what kind of RAM is needed? and any suggestions where to get it?
 

linkmon99

macrumors member
Jun 6, 2017
32
0
My apologies spinstoirm.

Alas Down Under the new iMac releases are yet to be posted on the Apple website so the information I posted was wrong. Both models use 8GB 2400MHz DDR4 as standard.

So I can buy any 2400MHz DDR4 ram and it should work on the new imacs?
 

Azenha

macrumors newbie
Jun 6, 2017
18
11
Apple has two webpages detailing the type of RAM needed for the 2017 27" iMac, but unfortunately they both have mistakes:

The support page mentions 204 pin SODIMMs (the correct is 260 pin): https://support.apple.com/en-us/HT201191

The online manual has the correct 260 pin but refers to the SODIMMs as PC4-2400 (the correct designation is PC-19200): https://help.apple.com/imac/mid-2017/#/apde7d36b188

So, in summary, the correct RAM type would be 260 pin DDR4-2400 SODIMM PC4-19200 memory.

There are 4 slots and you may use 4GB, 8GB and 16GB modules, for a maximum of 64 GB (4x16).

Regarding which brands and models specifically will work better with the 2017 27" iMac, nobody knows yet... Things like latency and other details could affect performance and stability. Past Macs have been known to be quite picky regarding 3rd party RAM, so I guess the safest bet is to wait for early adopters to get their hands on the computer and try out various RAM modules. That's what I'll do! ;)
 

xgman

macrumors 603
Aug 6, 2007
5,266
1,013
any "quality" sodimm 2400 ram should work and I've never had any problem in the past with 3rd party ram and several imacs.

Specs: DDR4 PC4-19200 • CL=16 • Unbuffered • NON-ECC • DDR4-2400 • 1.2V • 2048Meg x 64
 
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hurtmemore

macrumors member
Jan 9, 2017
46
24
Regarding which brands and models specifically will work better with the 2017 27" iMac, nobody knows yet... Things like latency and other details could affect performance and stability. Past Macs have been known to be quite picky regarding 3rd party RAM

How significant is this? I thought any reputable brand should perform as expected - standard ram type - what is specific about iMac that could cause issues more than any other computer?

Is it possible last gen-iMac had more trouble because it was rated for 1867 instead of the standard 1866?
 

starwager19

macrumors newbie
Jan 1, 2016
28
6
Specs: DDR4 PC4-19200 • CL=16 • Unbuffered • NON-ECC • DDR4-2400 • 1.2V • 2048Meg x 64

The Crucial memory linked by Robbo1 above (and the ones I linked to) have CL of 17, rather than 16. Is that important?
 

jmantn

macrumors 6502
Mar 13, 2012
494
110
Tn
Here's some 32GB configurations using 2 RAM Slots:

$249 - Corsair Vengance that seems to fit the bill CL 16:
https://www.amazon.com/Corsair-Vengeance-Performance-Unbuffered-CMSX32GX4M2A2400C16/dp/B01G26166W/ref=sr_1_4?s=electronics&ie=UTF8&qid=1496800573&sr=1-4&keywords=32gb+2400mhz+ddr4+sodimm


$259 - Kingston Hyper X Impact with a CL of 14
https://www.amazon.com/Kingston-Technology-HyperX-HX424S14IBK2-32/dp/B01BNJL8I4/ref=sr_1_1?s=electronics&ie=UTF8&qid=1496800573&sr=1-1&keywords=32gb+2400mhz+ddr4+sodimm

$259 - Ballistix Sport LT with a CL of 16
https://www.amazon.com/Ballistix-Si...eywords=DDR4+PC4-19200+CL16+2400+260+pin&th=1

$216 - Crucial With CL 17
https://www.amazon.com/dp/B019FRCV9G/ref=psdc_172500_t1_B01DGOF3E4


Unless I've overlooked something or unless the product page info is incomplete all of these should be compatible with the new Mid 2017 iMac's RAM slots.


EDIT:
Crucial's own website is now updated for 2017 iMac's.
http://www.crucial.com/ProductDispl...externalPartNumber=CT10559858&catalogId=10151
 
Last edited:

jmantn

macrumors 6502
Mar 13, 2012
494
110
Tn
I'm going with Ballistix I believe. I've had Corsair Vengance in a 2012 iMac and it lasted 4 years but did finally fail on me and the RMA turn around time was very long. So I ended up buying Crucial's Mac specific RAM for my iMac and also used Crucial for my MacBook Pro. Haven't had any issues since but then again I've not had Crucial for 4 years which isn't too bad. I've had memory on a PC fail as well and it did so around the 4 year mark so that may be typical.

I've looked here and on Apple Support Communities and see no issues with people using Ballistix in their Mac's and it's made by crucial. On Crucial's website which they've updated to list 2017 iMac compatible RAM it says Ballistix isn't compatible but every listed spec is the same:

Here's the Spec page for Ballistix from Crucial's website (note it's cheaper on Amazon and I've linked it above):
http://www.crucial.com/ProductDispl...ent_category_rn=&storeId=10151#productDetails

Here's the spec page for Crucial's Mac Memory for 32GB x2:
http://www.crucial.com/ProductDispl...externalPartNumber=CT10559858&catalogId=10151

The only spec that's missing that I can see is if the Ballistix is Single Ranked or not but since it's a gaming type of memory (which means it'll be good for vide editing etc..) I'd assume it's single ranked as well.

Posting this in case I'm missing something and someone could point it out otherwise I'm ordering this one.
 
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Bill Gates 007

macrumors newbie
Sep 26, 2014
2
0
Here's some 32GB configurations using 2 RAM Slots:

$249 - Corsair Vengance that seems to fit the bill CL 16:
https://www.amazon.com/Corsair-Vengeance-Performance-Unbuffered-CMSX32GX4M2A2400C16/dp/B01G26166W/ref=sr_1_4?s=electronics&ie=UTF8&qid=1496800573&sr=1-4&keywords=32gb+2400mhz+ddr4+sodimm


$259 - Kingston Hyper X Impact with a CL of 14
https://www.amazon.com/Kingston-Technology-HyperX-HX424S14IBK2-32/dp/B01BNJL8I4/ref=sr_1_1?s=electronics&ie=UTF8&qid=1496800573&sr=1-1&keywords=32gb+2400mhz+ddr4+sodimm

$259 - Ballistix Sport LT with a CL of 16
https://www.amazon.com/Ballistix-Si...eywords=DDR4+PC4-19200+CL16+2400+260+pin&th=1

$216 - Crucial With CL 17
https://www.amazon.com/dp/B019FRCV9G/ref=psdc_172500_t1_B01DGOF3E4


Unless I've overlooked something or unless the product page info is incomplete all of these should be compatible with the new Mid 2017 iMac's RAM slots.


EDIT:
Crucial's own website is now updated for 2017 iMac's.
http://www.crucial.com/ProductDispl...externalPartNumber=CT10559858&catalogId=10151
I'm going with Ballistix I believe. I've had Corsair Vengance in a 2012 iMac and it lasted 4 years but did finally fail on me and the RMA turn around time was very long. So I ended up buying Crucial's Mac specific RAM for my iMac and also used Crucial for my MacBook Pro. Haven't had any issues since but then again I've not had Crucial for 4 years which isn't too bad. I've had memory on a PC fail as well and it did so around the 4 year mark so that may be typical.

I've looked here and on Apple Support Communities and see no issues with people using Ballistix in their Mac's and it's made by crucial. On Crucial's website which they've updated to list 2017 iMac compatible RAM it says Ballistix isn't compatible but every listed spec is the same:

Here's the Spec page for Ballistix from Crucial's website (note it's cheaper on Amazon and I've linked it above):
http://www.crucial.com/ProductDispl...ent_category_rn=&storeId=10151#productDetails

Here's the spec page for Crucial's Mac Memory for 32GB x2:
http://www.crucial.com/ProductDispl...externalPartNumber=CT10559858&catalogId=10151

The only spec that's missing that I can see is if the Ballistix is Single Ranked or not but since it's a gaming type of memory (which means it'll be good for vide editing etc..) I'd assume it's single ranked as well.

Posting this in case I'm missing something and someone could point it out otherwise I'm ordering this one.

Thanks just bought the Ballistix 32GB from Crucial (Amazon doesn't ship to Australia) ordered 27 inch 1TB i7 8GB as well
 

Robbo1

macrumors member
Apr 4, 2017
39
20
The OWC 32GB kit (16Gbx2) is $280 and has a CL of 11 while the Crucial kit is $250 and has a CL of 17. I understand that lower CL is supposed to be faster but does it make a difference in Real world applications and is it worth the $30 extra? If I planned on keeping the 8GB of OEM memory to get me to 40GB will my memory speed be dictated by the OEM sticks (which I believe are CL16)? If that is the case would running 32GB at CL11 be noticeably faster than running 40GB at either CL 11/16 or CL 16/17?
 
Last edited:

trsblader

macrumors 6502
May 20, 2011
449
202
The OWC 32GB kit (8Gbx2) is $280 and has a CL of 11 while the Crucial kit is $250 and has a CL of 17.

I was on macsales looking at this for my upgrades, and they list their 32gb (8x4) from OWC as CL17 as well. Can't speak for the rest of it though.

macsales has a new section for the 2017 iMac's in case anyone else is looking at ram options and just wants to verify correct specs
 
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