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16 GB RAM in iMac 2010 - random shutdowns?

Mac Hammer Fan

Mac Hammer Fan

macrumors 65816
Original poster
Jul 13, 2004
1,352
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My friend bought an Imac. I gave him the advice to buy 16 GB RAM not from the Applestore. It's an Imac 27 inch Quad 2.93 with 256 GB SSD and 2TB harddisk. Now I hear that 16 GB RAM can cause a lot of trouble in iMacs. There are several stories of random shutdowns in Apple Forums. Is there anyone from you who did have bad experiences with 16 GB RAM in a iMac 2010?
 
You're going to find plenty of complaints and reports of troubles on forums, as that's just the nature of them. I don't have 16gb of ram in my iMac myself, but I've run across many people on here who have 16gb of ram in theirs with no problems.

I wouldn't worry about it.
 
I had 16 GB of NuRam from OWC and experienced those problems. Random shutdowns and sometimes would freeze at startup as well. I sent the RAM back, but took a little loss because the price had changed since I bought.

Later read only the original RAM (Samsung brand I believe) has had a good success rate with a 16GB configuration. I haven't done tons of research so I don't question anyone who says otherwise. This is just from my experience with only one brand of memory.

I plan to buy the OWC brand this month, but in a 12 GB configuration. Hope that helped.
 
In case that I have problems with 16 GB RAM, which configuration is recommended?
2x4 GB RAM and 2x2 GB RAM = 12 GB RAM
or 3x4GB RAM and 1x 2GB RAM = 14 GB RAM
Does an iMac use dual channel memory?
The Imac should arrive next week. Hopefully.
 
16gb seems fine here

Have a 2010 Core i7 2.8 with 16gb, its been the most stable machine i've ever had (but i was a windows fanboi until about 9 months ago).

I did buy the machine with 16gb direct from Apple.
 
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Mac Hammer Fan said:
My friend bought an Imac. I gave him the advice to buy 16 GB RAM not from the Applestore. It's an Imac 27 inch Quad 2.93 with 256 GB SSD and 2TB harddisk. Now I hear that 16 GB RAM can cause a lot of trouble in iMacs. There are several stories of random shutdowns in Apple Forums. Is there anyone from you who did have bad experiences with 16 GB RAM in a iMac 2010?
Click to expand...

If you've been following the threads in the Apple Support Forums, then you'll know that there is probably enough anecdotal evidence to say rather definitively that we should not be assuming that anything other than Samsung or Apple-installed Hynix is going to work perfectly in the 4 x 4 GB configurations.

It took a while for people to reach the conclusion that it was the brand of 16 GB memory that was causing the problem, and not that it was an iMac 2010 problem with 16 GB.

Some of us have received unilaterally initiated phone calls from Apple support personnel because of our posts in those forums. I am one of them.

It's possible you might see some updates from Apple intended to broaden the 2010 iMac's acceptance of cheaper RAM, but at the moment they seem to be saying over the phone that it's a problem with the strictness with which the RAM manufacturers read and complied with the specifications of the Samsung RAM that was the RAM that Apple used for their testing and recommendations for compliance.

Personally, I am comfortable saying (based on my own experience and a compilation of the anecdotal evidence at the Apple Support Forums) that if you are sure that you must have 16 GB of RAM in your 2010 iMac, you should either buy it that way from Apple or buy the Samsung (or Hynix) memory.

: runs for cover :
 
Mac Hammer Fan said:
In case that I have problems with 16 GB RAM, which configuration is recommended?
2x4 GB RAM and 2x2 GB RAM = 12 GB RAM
or 3x4GB RAM and 1x 2GB RAM = 14 GB RAM
Click to expand...

For whatever it is worth, there are more success stories with off-branded 12 GB configurations than there are with off-branded 14 GB configurations.

Your 14 GB configuration might work, but Apple recommends that you have identical chips in each of the two banks.

So in theory your chances are much better with the 12 GB.

In my case, my computer threw a rod over the Crucial memory kit (wouldn't even start properly), and then objected to my second attempt with cheap OWC RAM (random shutdowns).

I decided not to take any chances and stepped down to 2 x 4 GB Samsung + 2 x 2 GB Samsung = 12 GB.

My decision had to be made before we had enough people posting in the Apple Support Forums for an end user to reasonably extrapolate a logical assumption that he should only be buying Samsung or Hynix if he wanted 16 GB.

Based on what I know now, I'd have gone with 4 x 4 GB Samsung. But I don't need it badly enough to buy anything else, and I am hardly going to take Apple up on their extraordinary offer of an exchange just because I do not have 4 extra GB of RAM.

I still cannot believe they offered to do that, but it's basically sold me on Apple, pretty much for life, if I weren't sold on them before.

:)
 
sbeezy said:
I plan to buy the OWC brand this month, but in a 12 GB configuration. Hope that helped.
Click to expand...

For whatever it is worth, OWC's Samsung prices are very competitive. If you really want 16 GB, they have a decent price.

My OWC RAM that wouldn't work right, I have to say, they were very decent about taking back and refunding very quickly. I'd still buy from OWC in a heartbeat because of what has been excellent service so far.

Something that surprised me was how BAD service was from Crucial. I had always had good service from them in years past, but this year they really screwed up. They didn't even answer my requests for an RMA, or emails asking about the problem.

I ended up having to sell the Crucial RAM myself, taking a loss because of course I'd have to reveal that the memory didn't work properly in the only machine I'd tried.

Needless to say, I doubt I'll be sending any money Crucial's way for a couple of decades. :)
 
George Knighton said:
... they seem to be saying over the phone that it's a problem with the strictness with which the RAM manufacturers read and complied with the specifications of the Samsung RAM that was the RAM that Apple used for their testing and recommendations for compliance.
Click to expand...

Did Apple actually say this to you?
 
Satoneko said:
Did Apple actually say this to you?
Click to expand...

They said outright that they'd got my information from posts at the Apple Support Forums.

A second call said outright that they were sure the machines they'd tested so far complied with their specifications, and that other RAM must not be compliant.

A third contact hinted that they might consider changes that might allow cheaper RAM to work without problems.

I elected to hang onto my iMac instead of dealing with sending it back just to get an extra 4 GB of RAM free. It seems extraordinarily good service for them to have gone through all that. I do not understand why they would volunteer to take care of somebody else's problem, but it is certainly service above and beyond.
 
George Knighton said:
They said outright that they'd got my information from posts at the Apple Support Forums.

A second call said outright that they were sure the machines they'd tested so far complied with their specifications, and that other RAM must not be compliant.

A third contact hinted that they might consider changes that might allow cheaper RAM to work without problems.
Click to expand...

Thank you for the response.

I just want to let people know that this problem occurs not only with 16GB or third-party RAMs. It does happen with less than 16GB and Apple-installed RAM.

I purchased a build-to-order iMac 27” 2.93 GHz Intel Core i7 (1 TB HDD, 8 GB memory) in August. The random shutdowns started in September, once or twice a week. In November, I sent it in to the Apple Authorized Service Provider where they replaced the power supply unit. The iMac shut down in 15 minutes after returning from the repair. I sent it to repair again in December, they replaced the PSU again, and the iMac shut down one day after it came back. So, I took the advices on the Apple Support Discussion and switched my factory-installed 8GB Micron Technology RAMs to Samsung RAMs, and all my problems were solved instantly.

Here is the summary of my observations:

1) Memory-related random shutdowns can occur with Apple-installed memories. Apple uses OEM RAMs of three manufacturers: Samsung, Hynix, and Micron. Apparently, back in August 2010, Micron RAMs did not quite meet the Apple specs.

2) Memory-related random shutdowns can occur with any amount of memories. If you read through the Apple Support Discussions carefully, there are reports of shutdowns occurring with 4, 8, 12, and 16GB. However, overwhelming numbers of reports are from people who upgraded to 16GB. I speculate this is because the people who upgrade their own memory can clearly see the cause-effect: replacing memories results in shutdowns.

3) Incompatibilities are reported with third party RAMs from OWC (NuRam), Crucial, Transcend, and Corsair. Incompatibility is not reported with Samsung. It’s also been reported that 16GB Samsung works fine.

4) Incompatibilities do not show up on Apple Hardware Test or other RAM tests like Rember. Exactly why the RAM incompatibility makes the iMac shutdown is unknown.

I’ve been a Mac user for 20 years, and I’ve been able to solve most Mac problems on my own, or a call to the Apple Support would have fixed things. Apple does not seem to want to make this RAM issue official (I can understand if it’s the RAM manufacturers’ problem), and if it were not for the collective intelligence on the Internet, I would have never figured this out. So I thank all the people who posed about this problem, speculated on the cause, and struggled to come up with a remedy. I hope this helps others with this problem.
 
Random Shutdown...

I bought an i7 27inch w/16gb of RAM and experienced the same random shutdown problem as many of you have. I read dozens of forum entries and thank everyone for posting.

I needed to come back and let everyone know how I solved, or rather Apple, solved this.

I repeated told them to double check the RAM and after doing due diligence and checking everything under the hood, the Apple tech discovered that they had installed the wrong type of RAM. They put the older, slower RAM, which is fine for other systems, but not our ultra new components.

The correct RAM is 1066MHz.

Possibly something that others may check if they have not had any success solving this problem.

Thanks again to everyone for posting! Without your research I wouldn't have known where to start! :D

anjosef
 
I've been experiencing the same problem.

My iMac is new, 27" 2,8 GHz, and comes with 4 GB Samsung. No Problem.

When I change the 4 GB with 16 GB CSX, I experience random shutdowns. Curiously, I can force this shutdown sometimes simply visiting, with Firefox, the site Marca.com. But sure this site is not the cause of the problem.

I've uninstalled again the 16 GB Ram CSX and installed 4 GB from Apple (Samsung). No problem, no shutdowns.

Then, I'm thinking to return CSX memory and buy Samsung. I think I will need all 16 GB RAM to work with Audio, Virtual Instruments, Orchestral Libraries and more.
 
Ah nevermind. Also, this appears to be localized to the i5 and i7 model (i3 here) so I don't think I'll need to be concerned.
 
The shop (Macnificos, Spain) where I bought 4 modules of 4 GB of Ram that causes random shutdowns on my iMac 27, has been in contact with the distributor and manufacturer of CSX Ram because some other clients experienced the same problem.

They affirm that shutdown problem is an electric problem of iMac, not a problem of Ram modules, and they are sure that can ocurr when the machine has 16 GB of Ram installed and with some specific modules. CSX can't found any problem on their modules, so they think their RAM is OK, and assure that the problem is random and also can ocurr with Samsung RAM. They think perhaps my modules are defective. I'm not agree with this explanation.

They accept to change my four 4GB modules of CSX RAM with four new identical modules. I will try it all next week, and I will warn you if the problems persist with the new modules, but I'm sure that shutdowns will be continued ocurring because the modules that they're sending to me are identical to that already I have.
 
Try to use Hynix or Samsung RAM.
My iMac (i7) came with 2x4GB Hynix modules and I was lucky, having bought another 2x4 of exactly the same manufacturer, even the part numbers are matching.
Enjoying 16GB here for a bit over a week now, no problems whatsoever so far (knocking on wood).
 
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I just received my i7 today and had ordered the 16gb upgrade kit from OWC and just installed it. Going to encode some videos and hope for the best. So far so good but will keep you all posted
 
I've found that the culprit is almost always cheap RAM. Never purchase RAM by price, purchase by brand reputation.
 
Thank you for the heads up, good to know. It would interesting to know, especially from European users, where you are sourcing your memory. I am finding it very hard to find any dealers over here who carry Samsung or Hynix. Worse, with some dealers it seems to be a lottery which brand you will receive.
 
I have a 2010 27 iMac and I ordered a 16gig ram from owc never had any problems and it's runs like a dream
 
Well, the Hynix RAM was actually very cheap.
Got it from eBay Germany for less than 100 Euros (8GB).
This eBay search should find it.
They have Samsung RAM, too. If you don't want to replace but simply upgrade your memory, I suggest you buy the same brand that's built in by Apple.
 
I've not had any issues with 4x4GB of G.Skill F3-8500CL7S-4GBSQ; and, that's not even their Apple approved modules. $160 (minus what you sell your 2GB sticks for) for 16GB :)
 
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