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What RAM to buy to update new iMac launched today?

guibo said:
this is far from an optimal approach. ram is sold in pairs for a reason, you need well matched ram for it to work well in dual channel. even if you match specs, a future RAM stick will not be a perfect pair. consequences of that can range from a small speed loss to system instability as it forces dual channel.
Click to expand...

Populating dual channel memory isn't as simple as most people believe.

As well as working with paired RAM across banks, it also works with equal quantities of equivalently timed RAM in each bank.
 
Could somebody please confirm a proper description of RAM people need to buy?
Is it: 2400MHz SODIMM 260 Pin?
 
hey guys! Long time lurker but first time iMac owner as I needed something for video rendering. I've never used MAC OS so there is a lot of things to learn but I ended up getting the lowest option i5 3.4GHz. Once I got it i upgraded the memory right away because I mean 8GB was just too little with what I needed to accomplish.

eiGsR4k.jpg


https://www.amazon.com/Adamanta-Mem...d=1498060205&sr=8-4&keywords=imac+2017+memory

I have been using this kit for the past week now and no hiccups. Just wanted to give anyone a heads up that needs memory as I know Crucial is out of stock and OWC prices are just a bit too high.

Cheers!

sosnooly said:
Could somebody please confirm a proper description of RAM people need to buy?
Is it: 2400MHz SODIMM 260 Pin?
Click to expand...

yes that is correct
 
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Just added 32GB of the Crucial memory to my 2017 base 27"and everything works great.

Crucial 32GB

I'll save replacing the OEM modules for a later date.
 
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fcracer said:
Thanks again Onionbobo for doing the research for us. I followed your advice and went with #4 above. I added another 2x8GB chips to go along with the 2x16GB ones I previously purchased. All four chips state CL14 for the HyperX. The computer now runs at DDR4 2400MHz.

Here are the Geekbench scores:

View attachment 704770
Click to expand...

WOW! Fantastic work, you are making me wanting more ram now :D No worries, happy to share my experience.
 
vintagebob said:
Just added 32GB of the Crucial memory to my 2017 base 27"and everything works great.

Crucial 32GB

I'll save replacing the OEM modules for a later date.
Click to expand...
But Apple's site says to use PC4-2400
 
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ammon said:
Just checked now, and its up to $283. But based on the pricing history, I don't see the price fluctuations directly related to the new iMac release...

View attachment 704771
Click to expand...

Thanks for the CCC price trend chart. The data points are very interesting. Maybe I just got lucky then. I paid $200 for my RAM and it shoots up to to $270+ in 7 days as people here post that Crucial is OOS on their modules and many online retailers were out as well. Maybe it was just coincidental price increase but knowing how Jeff Bezos love data metrics and all, I'm a bit suspicious ;-)
 
mtchairs said:
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
Click to expand...

I ordered the CT2K16G4SFD824A kit (marketed by Crucial as "not compatible" for the 2017 27" iMac) and installed it when my computer arrived yesterday.

170622-cruc1.jpg


170622-cruc2.jpg


I put it it in the empty slots, as such:

170622-config.jpg

(Is this the best possible choice of placement of the Crucial RAM together with the stock 2x4 GB?)

This is the system config with only the stock RAM:

170622-geek8.jpg



Memory related scores for this config are:

Single-Core Memory Copy 4528 (12.5 GB/sec)
Single-Core Memory Latency 6593 (65.7 ns)
Single-Core Memory Bandwidth 3552 (19.0 GB/sec)

Multi-Core Memory Copy 4674 (13.0 GB/sec)
Multi-Core Memory Latency 6476 (66.9 ns)
Multi-Core Memory Bandwidth 4283 (22.9 GB/sec)

https://browser.geekbench.com/v4/cpu/3186068


This is the system config with the Crucial RAM:

170622-geek40.jpg


Memory related scores for this config are:

Single-Core Memory Copy 5615 (15.6 GB/sec)
Single-Core Memory Latency 5928 (73.0 ns)
Single-Core Memory Bandwidth 5018 (26.8 GB/sec)

Multi-Core Memory Copy 6604 (18.3 GB/sec)
Multi-Core Memory Latency 5909 (73.3 ns)
Multi-Core Memory Bandwidth 5577 (29.8 GB/sec)

https://browser.geekbench.com/v4/cpu/3186218


I was anxious to get to work, so I didn't bother taking the stock 2x4 GB RAM out to test only the 2x16 GB Crucial RAM, so I can't say if the increase in latency would disappear with this configuration.
 
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I might be alone here, but I doubt it...
There are so many different competing claims about memory in this thread.
Would it be possible to summarize the memory that is known to work and give good performance?
I have an iMac with the stock 8GB coming and want to purchase 2x8GB sticks to give me a total of 24GB. Unless it's inappropriate to mix. But honestly, I'm pretty technical but my eyes are definitely glazing over on the CL 14vs17 and dual rank vs single rank talk.

Perhaps just links to the products on the Crucial or Kingston sites? Or what ever recommendation you have would be great. I'm pretty lost.
TIA,
JayFromNoVa
 
Arctic Moose said:
I ordered the CT2K16G4SFD824A kit (marketed by Crucial as "not compatible" for the 2017 27" iMac) and installed it when my computer arrived yesterday.

170622-cruc1.jpg


170622-cruc2.jpg


I put it it in the empty slots, as such:

170622-config.jpg

(Is this the best possible choice of placement of the Crucial RAM together with the stock 2x4 GB?)

This is the system config with only the stock RAM:

170622-geek8.jpg



Memory related scores for this config are:

Single-Core Memory Copy 4528 (12.5 GB/sec)
Single-Core Memory Latency 6593 (65.7 ns)
Single-Core Memory Bandwidth 3552 (19.0 GB/sec)

Multi-Core Memory Copy 4674 (13.0 GB/sec)
Multi-Core Memory Latency 6476 (66.9 ns)
Multi-Core Memory Bandwidth 4283 (22.9 GB/sec)

https://browser.geekbench.com/v4/cpu/3186068


This is the system config with the Crucial RAM:

170622-geek40.jpg


Memory related scores for this config are:

Single-Core Memory Copy 5615 (15.6 GB/sec)
Single-Core Memory Latency 5928 (73.0 ns)
Single-Core Memory Bandwidth 5018 (26.8 GB/sec)

Multi-Core Memory Copy 6604 (18.3 GB/sec)
Multi-Core Memory Latency 5909 (73.3 ns)
Multi-Core Memory Bandwidth 5577 (29.8 GB/sec)

https://browser.geekbench.com/v4/cpu/3186218


I was anxious to get to work, so I didn't bother taking the stock 2x4 GB RAM out to test only the 2x16 GB Crucial RAM, so I can't say if the increase in latency would disappear with this configuration.
Click to expand...

I installed the same config and the same memory kit: i7 4.2GHz/ 1TB SSD/ Radeon 580/ 40GB RAM
I put the crucial into the empty slots as well so it's 4_16_4_16

memory.png


I rebooted my iMac, ran Geekbench and left it alone until it was done. My numbers are:
geekbench.png


Honestly, people are getting hung up on scores but the simple truth is, this is the fastest Official Apple Mac (non-Hackintosh) ever from a single core perspective. It's crazy fast. And I wonder if Geekbench will spit out the exact same numbers if you run it over and over?
 
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jayfromnova said:
I might be alone here, but I doubt it...
There are so many different competing claims about memory in this thread.
Would it be possible to summarize the memory that is known to work and give good performance?
I have an iMac with the stock 8GB coming and want to purchase 2x8GB sticks to give me a total of 24GB. Unless it's inappropriate to mix. But honestly, I'm pretty technical but my eyes are definitely glazing over on the CL 14vs17 and dual rank vs single rank talk.

Perhaps just links to the products on the Crucial or Kingston sites? Or what ever recommendation you have would be great. I'm pretty lost.
TIA,
JayFromNoVa
Click to expand...

Just people chasing those extra percentage points. Looks good in the benchmarks, but in real-world performance there is no difference.

The best from a value perspective is to go with either of the Crucial parts that are not marked specifically for Mac. One is dual-sided and the other single-sided. No real difference there and either will work.

OWC and Crucial want a premium for the Mac-specific stuff for no good reason and the Kingston CL14 stuff requires you to dump the included memory - not a good value.
 
canadaeh? said:
I installed the same config and the same memory kit: i7 4.2GHz/ 1TB SSD/ Radeon 580/ 40GB RAM
I put the crucial into the empty slots as well so it's 4_16_4_16

View attachment 705280

I rebooted my iMac, ran Geekbench and left it alone until it was done. My numbers are:
View attachment 705281

Honestly, people are getting hung up on scores but the simple truth is, this is the fastest Official Apple Mac (non-Hackintosh) ever from a single core perspective. It's crazy fast. And I wonder if Geekbench will spit out the exact same numbers if you run it over and over?
Click to expand...

I took your advice and ordered the Crucial today from Amazon for $216.87 as of right now. I think this is a solid price for this RAM and I think your right about people getting hung up on scores. The real world difference won't be any at all and if it is I'm sure its extremely minor. For anyone else interested in ordering, here is the link. I would buy quickly as the price can change any minute. https://www.amazon.com/Crucial-16GB...fered+SODIMM+260-Pin+Memory+-+CT2K16G4SFD824A
 
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fcracer said:
That's correct. 1,3 or 2,4. If you put two sticks in 1,2, most speed measures drop by half.
Click to expand...
Interesting. So this is wrong then?

iMac2017MemoryWrong_zpstgtreyw3.png


And this is right (my current configuration)?

iMac2017MemoryRight_zps23qfen3x.png


Does this apply to all iMacs?

Note that I bought Crucial RAM. It doesn't matter what configuration I choose: It always boots just fine. That's why I always just get the RAM with the exact specs instead of faster RAM or whatever. If I get the latter, it sometimes doesn't boot, or else sometimes only boots in specific configurations.
 
Last edited:
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BuCkDoG said:
I took your advice and ordered the Crucial today from Amazon for $216.87 as of right now. I think this is a solid price for this RAM and I think your right about people getting hung up on scores. The real world difference won't be any at all and if it is I'm sure its extremely minor. For anyone else interested in ordering, here is the link. I would buy quickly as the price can change any minute. https://www.amazon.com/Crucial-16GBx2-PC4-19200-Unbuffered-260-Pin/dp/B019FRCV9G/ref=sr_1_1?ie=UTF8&qid=1498176974&sr=8-1&keywords=Crucial+32GB+Kit+(16GBx2)+DDR4+2400+MT/s+(PC4-19200)+DR+x8+Unbuffered+SODIMM+260-Pin+Memory+-+CT2K16G4SFD824A
Click to expand...
I also use this RAM (CT2K16G4SFD824A) I spent $216 with no tax and free shipping from BHPhoto.

I ran a 14 hour burn in of memtest (10 loops) and it passed with no errors.

I've also been using my system for a week now with no issues or such. I'm convinced that this is the best value RAM you can currently get for the 2017 iMac.

As you said, RAM with lower CL is available but your talking about 0.01 second increase in real world apps. I saved over $75 compared to what some people were paying for memory with lower CL. Not trying to burst any bubbles but I'm happy with my choice :)
 
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btrach144 said:
I also use this RAM (CT2K16G4SFD824A) I spent $216 with no tax and free shipping from BHPhoto.

I ran a 14 hour burn in of memtest (10 loops) and it passed with no errors.

I've also been using my system for a week now with no issues or such. I'm convinced that this is the best value RAM you can currently get for the 2017 iMac.

As you said, RAM with lower CL is available but your talking about 0.01 second increase in real world apps. I saved over $75 compared to what some people were paying for memory with lower CL. Not trying to burst any bubbles but I'm happy with my choice :)
Click to expand...

I'll save the $75 anyday versus a very very minor 0.01 performance increase with lower CL.
 
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Hello guys,

there are many posts and I tried to read them but I dont know much about RAMs so could someone help me which to choose:
* Kingstone HyperX Impact 2x16GB DDR4 2400MHz
* 2x Crucial Ballistix Sport LT 16GB 2666MHz

I have original 8GB RAM in iMac 27" 2017 (just bought) and I would like to keep them until I decide to buy another 2x16GB RAMs (this could be after year, 2 years or maybe later). So can I keep 8GB there? Which one is better for iMac? Kingstone or Crucial? I really dont know anything about CL, timing etc. So I am really looking for easy answer which should I buy :)

Thanks
 
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Libor said:
Hello guys,

there are many posts and I tried to read them but I dont know much about RAMs so could someone help me which to choose:
* Kingstone HyperX Impact 2x16GB DDR4 2400MHz
* 2x Crucial Ballistix Sport LT 16GB 2666MHz

I have original 8GB RAM in iMac 27" 2017 (just bought) and I would like to keep them until I decide to buy another 2x16GB RAMs (this could be after year, 2 years or maybe later). So can I keep 8GB there? Which one is better for iMac? Kingstone or Crucial? I really dont know anything about CL, timing etc. So I am really looking for easy answer which should I buy :)

Thanks
Click to expand...

I am not sure if you can still find compatible RAM after 2-3 years. This is my concern as well.
 
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