What RAM to buy to update new iMac launched today?

[hurtmemore]

@curmudgeonette

Do you know of any reason to get this over this?

Their recommended mac version is single ranked, while the regular set is dual.

But the mac version is on backorder and more expensive just about everywhere. Trying to figure if it's worth waiting or just go with the standard dual-ranked set. I see people seemingly having success with all kinds of ram, just don't understand what the benefits/risks are considering they all meet Apple's requirements.

 

[curmudgeonette]

Do you know of any reason to get this over this?

Their recommended mac version is single ranked, while the regular set is dual.

I think the "single rank" is a typo. Or more specifically, someone based the description on a 2x8 kit and overlooked the rank count.

I believe the Mac memory is guaranteed to fully work in a Mac. It might be harder to get a refund on the other kit. Be aware that Crucial has multiple part numbers that all are filled by the same physical part number. It lets them track the intended target and sort out incompatibility problems.

...

Approaching Crucial's site in a different way leads to this dual rank 2x16 kit for Macs:

Crucial part number: CT10559858

Out of stock - and the same higher price.

 

[fcracer]

I've learned so much from this forum so thought I'd give back in a small way by sharing what RAM has worked well on my new base model i5 mid-2017 iMac with 1TB SSD.

Kingston HyperX DDR4 2400 16x2 kit. Part number: hx424s14ibk2/32

When powering up the first time, I thought something was wrong because the screen didn't go white like my old iMac. It's actually supposed to be that way so don't worry, the new iMac powers up to a black screen with no chime.

I added the two 16GB memory chips into the open slots and now the computer has 40GB. I use Capture One Pro 10 for photo editing and was surprised to see it gobble up 14GB of RAM while editing photos from a recent trip to Myanmar.

I should note the computer shows 2133MHz when looking at the memory in the "about system" under the apple menu. Not sure if it does that with the factory RAM as well. The chips clearly state 2133-2666MHz so I'm not concerned.

 

[Echophage]

See also my post #141 where I report about these modules, I put 64GB in and until now the system running smooth

I take a screenshot from the system report, there all modules showing up with running at 2400MHz.

Maybe you can double check that on your machine if the modules alone running with 2400MHz.

 

[posguy99]

I should note the computer shows 2133MHz when looking at the memory in the "about system" under the apple menu. Not sure if it does that with the factory RAM as well. The chips clearly state 2133-2666MHz so I'm not concerned.

Read the data sheet for the Kingston RAM. It's overclocked. It lays out specific conditions for the RAM to run at 2400, and it sounds like the iMac does not meet those conditions. You should return it immediately.

Of course the correct answer is to never buy anything with Kingston's name on it. It's a shame, really, they used to be a great name, now all they are is a name slapped on no-name Chinese import-of-the-week.

 

[starwager19]

For the record, not that I have seen any doubt, I can confirm that the OWC 64GB kit works fine.

 

[Onionbobo]

Kingston HyperX DDR4 2400 16x2 kit. Part number: hx424s14ibk2/32



I should note the computer shows 2133MHz when looking at the memory in the "about system" under the apple menu. Not sure if it does that with the factory RAM as well. The chips clearly state 2133-2666MHz so I'm not concerned.

I've got the exact same issue. And I've figured out why and how to fix it.

1) To fix it, remove the stock ram, put your HyperX in slot 1 and 3 only, run as 32 gb. You will get 2400 MHz.

2) I've done a number of test and found running with HyperX 32gb only has the highest performance, infact, my iMAC has the highest score for 2017 model on Geekbench, better than stock 64gb.

https://browser.primatelabs.com/v4/cpu/search?dir=desc&q=iMac18,3&sort=score

3) The reason is HyperX has faster CL, only 14, where stock Apple ram has 17, therefor when you mix different CL speed, HyperX will slow down to 2133 MHz. Actually, it raised factory RAM's CL to 14, however, factory ram will slow to 2133 when CL@14 and force hyperx to 2133 as well. (Please correct me if I'm wrong)

4) If you want to run 4 rams, then ditch the Apple ram and get another set of 32gb Hyperx, you'll have 64GB and it will run at 2400 MHz.

5) I've done many test and 32GB HyperX alone is almost 10% faster than 40GB of mix factory RAM and Hyper X.

6) On my machine, if I leave factory ram in slot 1,3 and HyperX in 2,4, the iMac would not boot up, fan is working but black screen, waited 2 minutes. It does work if I put Hyperx in 1,3 and factory in 2,4. But will only run at 2133 MHz and much worse Geekbench scores.

Conclusion: Only run the same RAM across all slots. Remove your stock ram and run it with 32GB only. Or buy 2 more HyperX if you want 64gb. And HyperX is damn amazing. I think only people with 64GB HyperX can beat my Geekbench score.

 

[Trebuin]

I've got the exact same issue. And I've figured out why and how to fix it.

1) To fix it, remove the stock ram, put your HyperX in slot 1 and 3 only, run as 32 gb. You will get 2400 MHz.

2) I've done a number of test and found running with HyperX 32gb only has the highest performance, infact, my iMAC has the highest score for 2017 model on Geekbench, better than stock 64gb.

https://browser.primatelabs.com/v4/cpu/search?dir=desc&q=iMac18,3&sort=score

3) The reason is HyperX has faster CL, only 14, where stock Apple ram has 17, therefor when you mix different CL speed, HyperX will slow down to 2133 MHz. Actually, it raised factory RAM's CL to 14, however, factory ram will slow to 2133 when CL@14 and force hyperx to 2133 as well. (Please correct me if I'm wrong)

4) If you want to run 4 rams, then ditch the Apple ram and get another set of 32gb Hyperx, you'll have 64GB and it will run at 2400 MHz.

5) I've done many test and 32GB HyperX alone is almost 10% faster than 40GB of mix factory RAM and Hyper X.

6) On my machine, if I leave factory ram in slot 1,3 and HyperX in 2,4, the iMac would not boot up, fan is working but black screen, waited 2 minutes. It does work if I put Hyperx in 1,3 and factory in 2,4. But will only run at 2133 MHz and much worse Geekbench scores.

Conclusion: Only run the same RAM across all slots. Remove your stock ram and run it with 32GB only. Or buy 2 more HyperX if you want 64gb. And HyperX is damn amazing. I think only people with 64GB HyperX can beat my Geekbench score.

Thanks! This is exactly what I was looking for and was suspecting would happen.

 

[fcracer]

I've got the exact same issue. And I've figured out why and how to fix it.

1) To fix it, remove the stock ram, put your HyperX in slot 1 and 3 only, run as 32 gb. You will get 2400 MHz.

2) I've done a number of test and found running with HyperX 32gb only has the highest performance, infact, my iMAC has the highest score for 2017 model on Geekbench, better than stock 64gb.

https://browser.primatelabs.com/v4/cpu/search?dir=desc&q=iMac18,3&sort=score

3) The reason is HyperX has faster CL, only 14, where stock Apple ram has 17, therefor when you mix different CL speed, HyperX will slow down to 2133 MHz. Actually, it raised factory RAM's CL to 14, however, factory ram will slow to 2133 when CL@14 and force hyperx to 2133 as well. (Please correct me if I'm wrong)

4) If you want to run 4 rams, then ditch the Apple ram and get another set of 32gb Hyperx, you'll have 64GB and it will run at 2400 MHz.

5) I've done many test and 32GB HyperX alone is almost 10% faster than 40GB of mix factory RAM and Hyper X.

6) On my machine, if I leave factory ram in slot 1,3 and HyperX in 2,4, the iMac would not boot up, fan is working but black screen, waited 2 minutes. It does work if I put Hyperx in 1,3 and factory in 2,4. But will only run at 2133 MHz and much worse Geekbench scores.

Conclusion: Only run the same RAM across all slots. Remove your stock ram and run it with 32GB only. Or buy 2 more HyperX if you want 64gb. And HyperX is damn amazing. I think only people with 64GB HyperX can beat my Geekbench score.

Wow. I just did this exact same testing and had exactly the same outcome. I wish I'd known you were going to do this testing, I could have enjoyed a few beers instead of loading geekbench again and again

I guess I'll be picking up more ram!

 

[yadmonkey]

Sorry if I missed this, but when you get one of the new iMacs with 2 modules are they placed in slots one and three, leaving two and four open? Like below?

Stock: 4 - 0 - 4 - 0
Yours: 4 - 8 - 4 - 8 (after adding 2x8GB modules)

I can't remember if my Late 2013 iMac came that way too.

 

[dsc888]

I just ordered the HyperX as well but (4x8Gb) config for 32 Gb total. I took a good look at my usage under Activity Monitor and I rarely exceed 16 Gb with all my Apps open so this will do. I plan on selling my Apple OEM 8 Gb to help recoup some of the cost. Not bad for $200 off Amazon!

https://www.amazon.com/gp/product/B01BNJL4BK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I just wanted to chime in that this RAM is working just fine. It's CL15. All 4 sticks were immediately recognized by the new iMac. My Geekbench scores went up from 5500 to 5800 SC and 18000 to 20000 MC.

Talk about price gouging! I paid $200 even just a week ago and it's $272 now on Amazon! Everyone must be ordering up their stock.

 

[fcracer]

Sorry if I missed this, but when you get one of the new iMacs with 2 modules are they placed in slots one and three, leaving two and four open? Like below?

Stock: 4 - 0 - 4 - 0
Yours: 4 - 8 - 4 - 8 (after adding 2x8GB modules)

I can't remember if my Late 2013 iMac came that way too.

That's correct. 1,3 or 2,4. If you put two sticks in 1,2, most speed measures drop by half.

 

[SaSaSushi]

My new machine finally arrived and I popped my 2x16GB sticks of Crucial Ballistix Sport into the empty slots in addition to the stock RAM. It booted up perfectly and shows 40GB total RAM at 2400MHz.

I am currently running Migration Assistant to restore my old system from the TB external I was using to run the previous iMac and will do more comprehensive stress testing with Memtest once everything is back up and running. Looking good so far.

Incidentally, the stock Apple RAM is 2400MHz CL17 and the Crucial Ballistix is CL16.

 

[bry223]

Just received my crucial RAM from amazon today. No issues whatsoever. Seems to be the best priced for this type/speed I've seen so far, and it's in stock;

https://www.amazon.com/gp/product/B01BIWMWVS/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

 

[PRsolid]

I will recive my imac on monday, do i need to turn it on for The first time before switching the ram? Or can i just open it and switch them right away and Then turn it on for The first time ?

 

[SaSaSushi]

I will recive my imac on monday, do i need to turn it on for The first time before switching the ram? Or can i just open it and switch them right away and Then turn it on for The first time ?

There is no need to power on first. I popped in my additional RAM before I even plugged it in for the first time.

 

[PRsolid]

There is no need to power on first. I popped in my additional RAM before I even plugged it in for the first time.

Thanks!

 

[posguy99]

I just wanted to chime in that this RAM is working just fine. It's CL15.

So far people have said that the Kingston is CL14, CL15, and CL16. Yes, that's certainly something *I* want to buy.

 

[Floris]

I've learned so much from this forum so thought I'd give back in a small way by sharing what RAM has worked well on my new base model i5 mid-2017 iMac with 1TB SSD.

Kingston HyperX DDR4 2400 16x2 kit. Part number: hx424s14ibk2/32

When powering up the first time, I thought something was wrong because the screen didn't go white like my old iMac. It's actually supposed to be that way so don't worry, the new iMac powers up to a black screen with no chime.

I added the two 16GB memory chips into the open slots and now the computer has 40GB. I use Capture One Pro 10 for photo editing and was surprised to see it gobble up 14GB of RAM while editing photos from a recent trip to Myanmar.

I should note the computer shows 2133MHz when looking at the memory in the "about system" under the apple menu. Not sure if it does that with the factory RAM as well. The chips clearly state 2133-2666MHz so I'm not concerned.

stock 8gb (2x4) shows as 2400ddr4 on mine when i go to apple>about this mac.

btw, it's so strange the SSD isn't listed here..
[doublepost=1497743471][/doublepost]

Just received my crucial RAM from amazon today. No issues whatsoever. Seems to be the best priced for this type/speed I've seen so far, and it's in stock;

https://www.amazon.com/gp/product/B01BIWMWVS/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Thanks, I wish I had the extra 200 euro for the 32gb
https://www.amazon.de/gp/product/B019FRCV9G/ref=oh_aui_detailpage_o02_s00?tag=macr05-21&ie=UTF8&th=1
Maybe i should just not eat for a month and not think and buy it - get it over with. 200 including tax & shipping sounds pretty cheap.. i hope i get all the german correct.

 

[Brazilano]

iMac 27" i7.

Can I use 24gb (2 x 4gb Apple + 2 x 8gb Crucial)?

If not, which is the best option? Buy plus 2 x 4gb and put in iMac (2 x 4gb + 2 x 4gb Crucial = 16 gb) or buy 2 x 8gb (16 gb) and sell 2 x 4gb Apple?

 

[3drteest]

Crucial RAM at Provantage for only 242.17. Get it before it's gone.

http://www.provantage.com/crucial-technology-ct2k16g4s24am~7CIAL7K7.htm

 

[mtchairs]

Can anyone who has received their new iMac and installed this Crucial RAM from B&H confirm that it works ok?https://www.bhphotovideo.com/c/product/1208371-REG/crucial_ct2k16g4sfd824a_32gb_ddr4_2400_mhz.html

 

[davsv1]

Can anyone who has received their new iMac and installed this Crucial RAM from B&H confirm that it works ok?https://www.bhphotovideo.com/c/product/1208371-REG/crucial_ct2k16g4sfd824a_32gb_ddr4_2400_mhz.html

Well I can say that it works....but Ok is subjective, it works fine as far as I am concerned but I haven't done any speed tests, I have also installed it with the 8gig stock from apple.

 

[Sheza]

Quick question folks...

If I get the 8GB iMac, which I believe has 2x4GB, can I then buy a 2x8GB kit from Crucial and get 24GB in total, or is this not worth it? It's about the same cost as getting the Apple upgrade to 16GB/2x8GB. I'm not worried about future upgrades.

EDIT: I can see someone a few posts above has asked the same thing! Here's hoping we can get an answer from you lovely people

 

[KnoeSS]

Quick question folks...

If I get the 8GB iMac, which I believe has 2x4GB, can I then buy a 2x8GB kit from Crucial and get 24GB in total, or is this not worth it? It's about the same cost as getting the Apple upgrade to 16GB/2x8GB. I'm not worried about future upgrades.

EDIT: I can see someone a few posts above has asked the same thing! Here's hoping we can get an answer from you lovely people

I have done exactly that. 8GB from Apple, 16GB from crucial for a total of 24GB.
For me it was cheaper this way and I got more RAM.