What RAM to buy to update new iMac launched today?

[haruhiko]

I finally bought another pair (T_T) of Kingston 8GB DDR4 2400MHz SODIMM RAM (coz other brands are out of stock everywhere), which is not branded Hyper X, and with a correct number of CL17. This time all the RAMs are finally running at 2400MHz.

An expensive lesson for me as the computer store in Hong Kong does not accept returns (if it works in any form), and surprisingly it's legal to refuse return in Hong Kong. Even Apple itself doesn't accept returns here. Maybe this is why our electronics are much cheaper and available everywhere...

 

[Mike Boreham]

This RAM buying business is very frustrating! .....not least because Crucial seem to have different part numbers for the same item!

I have ordered CT2C8G4S24AM from Amazon. The page specifically mentions 2017 iMac 27, and is the "for Mac" version.

Crucial has the same CT2C8G4S24AM on its website which also says "for Mac" but does not mention 2017 iMac 27 specifically.

But if I use the "Will it work with my system? section on that page it leads to a different part number CT10559862 with completely identical product info and same price, but which does mention 2017 iMac 27 specifically.

From everything I have read, what I have ordered will be fine, but it sure is a confusing area.

 

[theluggage]

Why not just go through the Crucial advisor tool and order the part it recommends direct from that page? That way they've promised you compatibility with your specific system and (certainly under UK consumer law) are totally on the hook if there are any compatibility issues...

That may be one reason why they're giving different catalogue numbers to sticks sold via the adviser tool - (a) to identify such sales if there's any comeback and (b) maybe to discourage you from ordering the same part from Amazon...

Amazon are no cheaper - if you're on Prime you save the delivery cost, that's it: I'd say that's worth paying for a contractual commitment from the seller that the memory is compatible with your specific model of computer.

 

[Mike Boreham]

Why not just go through the Crucial advisor tool and order the part it recommends direct from that page? That way they've promised you compatibility with your specific system and (certainly under UK consumer law) are totally on the hook if there are any compatibility issues...

That may be one reason why they're giving different catalogue numbers to sticks sold via the adviser tool - (a) to identify such sales if there's any comeback and (b) maybe to discourage you from ordering the same part from Amazon...

Amazon are no cheaper - if you're on Prime you save the delivery cost, that's it: I'd say that's worth paying for a contractual commitment from the seller that the memory is compatible with your specific model of computer.

Thanks. Those are good points but I wanted to order from Amazon because I can collect from an Amazon locker close by, instead of waiting in for the delivery.

 

[SaSaSushi]

If you read through this thread you will see that the "For iMac" labeling by Crucial is irrelevant. The only difference (aside from a higher price) is probably the fact that it is Halogen free per Apple's environmental standards.

I've been using Crucial Ballistix RAM in my 2017 iMac for 8 months now with zero issues. On Crucial's site it is marked as incompatible with the 2017 iMac in giant red letters.

"For iMac" or not, you are extremely unlikely to have any problems with PC4-19200 Crucial RAM.

 

[Mike Boreham]

If you read through this thread you will see that the "For iMac" labeling by Crucial is irrelevant. The only difference (aside from a higher price) is probably the fact that it is Halogen free per Apple's environmental standards.

I've been using Crucial Ballistix RAM in my 2017 iMac for 8 months now with zero issues. On Crucial's site it is marked as incompatible with the 2017 iMac in giant red letters.

"For iMac" or not, you are extremely unlikely to have any problems with PC4-19200 Crucial RAM.

Thanks for the reassurance SaSaSushi, though as I said I am not really worried.

The confusion is that both part numbers say they are the "for Mac" version, (meaning no lead and halogen which I know is not essential anyway), but the CT10559862 part number additionally mentions being for iMac ("Upgrade for: Apple iMac (Retina 5K, 27-inch, 2017) iMac18,3"). The one I have ordered from Amazon
CT2C8G4S24AM does not mention iMac on the Crucial site (though it does on the Amazon page) although it seems to be identical in every detail.

 

[haruhiko]

For me it's even worse. For iMac 2017 means it can't work with the original RAM sticks. Never trust those kind of stickers. They're just marketing BS.

 

[Dave410]

Howdy,

I confess that I haven't digested all 657 posts in this thread (yet), but it seems that many have successfully upgraded the RAM in their 2017 27" iMacs without much trouble, either adding to the existing RAM or replacing it completely.

But how about this: Is there any performance advantage to buying faster and/or lower latency RAM than Apple recommends? When I was building PCs I always bought better and faster RAM than I needed because I would overclock the machine. You can't overclock a Mac, of course, but do you think you might get another percent or two with better RAM or is it best just to stick to Apple guidelines?

Any thoughts?

Cheers,
Dave

 

[SaSaSushi]

Is there any performance advantage to buying faster and/or lower latency RAM than Apple recommends?

Based on the benchmarks posted to this thread as well as my own testing, lower latency RAM will marginally improve performance in benchmarks. That said, you are very unlikely to notice an actual difference in daily usage.

Also, keep in mind that all modules will clock at the latency of the slowest part installed so that if you, for example add CL16 Crucial Ballistix alongside Apple's CL17 Micron as I have done, all of the RAM will run at the slightly slower CL17. (See Post #534 in this thread)

 

[Dave410]

Thanks, SaSaSushi. Good to know. I was thinking of complete replacement anyway.

You seem really up on this stuff. Can you recommend a compatible, fast, low-latency RAM for the 4.2 GHz i7 27-inch iMac I'm planning to buy soon? I was thinking of 64 GBs, even though I really don't need it.

Many thanks,
Dave

 

[SaSaSushi]

Thanks, SaSaSushi. Good to know. I was thinking of complete replacement anyway.

You seem really up on this stuff. Can you recommend a compatible, fast, low-latency RAM for the 4.2 GHz i7 27-inch iMac I'm planning to buy soon? I was thinking of 64 GBs, even though I really don't need it.

Many thanks,
Dave

Hey, Dave.

If you're only going to be using it on its own, a lot of users in this thread have had good experiences with the Kingston HyperX. It doesn't mix well with other brands but on its own is high performance.

As mentioned above, I went with Crucial Ballistix Sport which is also faster than the Apple stock RAM at CL16. In terms of quality, you can't go wrong with Crucial. They're the consumer arm of Micron, makers of much of the RAM Apple ships their Macs with.

Unfortunately, prices seem to have gone through the roof since I bought my Ballistix last June. They seem to be about double what I paid at the time.

By the way, I could've sworn I saw you mention Fukuoka. Great city! Probably my favorite in Japan although I only had the pleasure to visit once.

 

[Dave410]

Many thanks again, SaSaSushi. That's great info and I'm sure I'll be placing an order soon. Six months ago I was a PC guy, but now I have a MacBook Pro and I'm buying a high-end iMac. Apple is going to bankrupt me.

Yep, I mentioned I was in Fukuoka and then edited it out when I asked for a RAM recommendation. It's a great town and I'm sorry I was only there for one day on this trip. I travel for a living and I'm back in Honolulu now. Seattle tomorrow.

Are you originally from Takamatsu?

Cheers and thanks again!

 

[SaSaSushi]

Many thanks again, SaSaSushi. That's great info and I'm sure I'll be placing an order soon.

Let us know what you end up going with and how it works out for you.

Six months ago I was a PC guy, but now I have a MacBook Pro and I'm buying a high-end iMac. Apple is going to bankrupt me.

I was a PC guy up until 11 years ago when I bought my first Mac. Apple's been bankrupting me ever since.

Are you originally from Takamatsu?

I'm originally from New Jersey but I've been an expat here in Takamatsu for 24 years now.

Cheers!

 

[Dave410]

Okay, thinking hypothetically here, I noticed that the HyperX Impact 2400 MHz DDR4 SO-DIMMS have a discrepancy between the 32 GB (2 x 16 GB modules) kit and the 64 GB (4 x 16 GB modules) kit. Amazon and Newegg have the 32 GB kit for $259.79/kit, and the 64 GB kit through one of their third-party sellers is $632.97, all before tax. That means I could theoretically buy 2 32 GB kits for $113.39 less than one 64 GB kit. Also, the CL rating on the 32 GB kit is 14, whereas the CL rating on the 64 GB kit is 15, and as we all know, the lower the CL value the better. Is there any kind of unspoken limitation to where anything higher than 32 GB must have a CL of 15 or higher? Again, just thinking hypothetically about getting a 27-inch iMac and maxing its memory out with the fastest modules possible for future-proofing purposes...

Hello again,

I've read or skimmed every post in this thread and never saw the answer to killermike's question. How come buying two of the Kingston HyperX 2x16 kits is over $200 cheaper than buying one of the 4x16 kits? I understand the 4x16 would be matched, but $200? Furthermore, the 2x16 kit has a CL of 14 while the 4x16 kit of the same RAM has a CL of 15. What gives?

Here are the links so you can see what I mean:

https://www.amazon.com/Kingston-Technology-HyperX-HX424S14IB-16/dp/B01BNJL8I4/ref=sr_1_1?ie=UTF8&qid=1497014540&sr=8-1&keywords=Kingston+HyperX+Impact+(HX424S14IB/16)&th=1

https://www.amazon.com/Kingston-Technology-HyperX-HX424S14IB-16/dp/B01BNJL7W6/ref=sr_1_1?ie=UTF8&qid=1497014540&sr=8-1&keywords=Kingston+HyperX+Impact+(HX424S14IB/16)&th=1

Or you can just flip back and forth between them using the little button on the web page.

In any case, I've been doing my homework and I'm planning on the top-end 4.2 GHz I7 iMac and 64 GB of Kingston HyperX. I may have to sell a kidney to pay for it, but that's my plan.

Cheers,
Dave
[doublepost=1519794237][/doublepost]

I'm originally from New Jersey but I've been an expat here in Takamatsu for 24 years now.

I envy you. I travel to Japan almost every month and I could live there real easy. Kanpai!

 

[SaSaSushi]

I've read or skimmed every post in this thread and never saw the answer to killermike's question. How come buying two of the Kingston HyperX 2x16 kits is over $200 cheaper than buying one of the 4x16 kits? I understand the 4x16 would be matched, but $200? Furthermore, the 2x16 kit has a CL of 14 while the 4x16 kit of the same RAM has a CL of 15. What gives?

Hey Dave,

The matching sets are tested as sets all together which some users claim gives better performance as well as a lower risk of compatibility issues.

I bought my two Crucial Ballistix 16GB modules separately though to save a ton of money and have had zero issues. YMMV.
[doublepost=1519801299][/doublepost]

I envy you. I travel to Japan almost every month and I could live there real easy. Kanpai!

It's a comfortable place to live for sure. Cheers.

 

[Dave410]

Hey Dave,

The matching sets are tested as sets all together which some users claim gives better performance as well as a lower risk of compatibility issues.

I bought my two Crucial Ballistix 16GB modules separately though to save a ton of money and have had zero issues. YMMV.

Makes sense, but why is one CL 14 and the other CL 15? It's the same stuff.

 

[SaSaSushi]

Makes sense, but why is one CL 14 and the other CL 15? It's the same stuff.

Sorry about that. I should actually learn to click on links before commenting. I assumed in this case.

A quick check of the datasheets at Kingston for these two products shows that, in fact, that 4x16GB set, HX424S15IBK4/64 is CL15.

The 2x16GB set, HX424S14IBK4/32 is CL14.

I have no idea why the 2x16GB sets are so much cheaper, but they're faster so I would definitely recommend them.

Sorry, you had also already mentioned the matching set theory in the comment I replied to. I need to read better too.

 

[Dave410]

Thanks again, SaSaSushi. The differences in latency make no sense to me. I asked Kingston about it yesterday, but no reply yet. I suppose it could be a probability thing during testing. Two sticks together have a higher probability of CL 14 than four sticks together, or something like that. Plopping four sticks of CL 14 into the computer might yield CL 15 when they start working together. Doumo Arigatou!

 

[Dave410]

A quick check of the datasheets at Kingston for these two products shows that, in fact, that 4x16GB set, HX424S15IBK4/64 is CL15.

The 2x16GB set, HX424S14IBK4/32 is CL14.

I have no idea why the 2x16GB sets are so much cheaper, but they're faster so I would definitely recommend them.

I heard back from Kingston and the tech said:

"Besides each part being a different kit size, the base part numbers are different. The first one is HX424S14IB and the second is HX424S15IB. The part numbers indicate the difference in CAS latency."

It looks like the faster one will save me over $200, if they ever get it in stock....

 

[briloronmacrumo]

A reliable supplier for me has been Data Memory Systems.
With excellent return policies and helpful folks both on the phone and via online chat.
Been a happy customer with them for many years.

 

[Dave410]

A reliable supplier for me has been Data Memory Systems.
With excellent return policies and helpful folks both on the phone and via online chat.
Been a happy customer with them for many years.

Thanks. I just searched their site and, sadly, didn't find Kingston HyperX. Cheers.

 

[SaSaSushi]

"Besides each part being a different kit size, the base part numbers are different. The first one is HX424S14IB and the second is HX424S15IB. The part numbers indicate the difference in CAS latency."

Yeah they're different parts which is why I can't understand why Amazon is charging so much more for the slower one.

Looks like you've got about a week or so until Amazon restocks.

Something else you could try is to get that Kingston tech on the horn again and see if he knows another retailer for it.

 

[Dave410]

Yeah they're different parts which is why I can't understand why Amazon is charging so much more for the slower one.

Looks like you've got about a week or so until Amazon restocks.

Something else you could try is to get that Kingston tech on the horn again and see if he knows another retailer for it.

It's surprising to me too that less performance costs more. Maybe Amazon mispriced it or they think people won't notice. Or else their computers are figuring out supply and demand and know the market will bear that price for that product. Amazon is pretty smart that way.

No hurry. I haven't even ordered the iMac yet. Still doing my homework and I'll be heading back to Asia soon so I'll probably wait until I get home to take care of this. Cheers.

 

[briloronmacrumo]

Thanks. I just searched their site and, sadly, didn't find Kingston HyperX. Cheers.

They don't carry Kingston products and never have( didn't mean to mislead ), if I remember correctly, but their standard RAM DIMMs and their service are excellent.

 

[Dave410]

No worries. Thanks.