New 27" 2010 iMac i7 Memory Issues

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New 27" 2010 iMac i7 Memory Issues

I know that numerous people have been experiencing issues with upgrading to 16gb of ram in the new 27" i7's. For some reason, when you have 4 modules installed weird things start to happen. Freezes and random shut downs are the main issues. If you remove two of the modules everything goes back to normal. Here are two threads that talk about it as well.

http://discussions.apple.com/thread.jspa?threadID=2567907&tstart=15
http://discussions.apple.com/thread.jspa?threadID=2576477&tstart=75

I went through 3 different 16gb kits from OWC and all three ended up making my mac randomly shut down for now reason. Total loss of power. If I put the 4gb apple memory back in everything works fine.

Here is a link to the OWC memory - http://eshop.macsales.com/item/Other%20World%20Computing/1333DDR3S16S/

Here is a link to the Crucial memory -
http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=769226C4A5CA7304

Both Crucial and OWC meet all specifications for Apple. I just installed 16gb of Crucial memory today, it came as two 8gb kits. I'm hoping it works but that would defy logic, there is no way that 3 sets of OWC memory were bad. I will keep you posted. It normally takes a good 24-48 hours for the issue to present itself, at least on my machine.

And please post if you are having the same issue, any information will help. Hopefully we can get this resolved.

Thanks

Message was edited by: labeck

iMac 27" Core i7 - Mid 2010 - 16gb Ram, Mac OS X (10.6.4)

Posted on Sep 21, 2010 12:37 PM

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Answer 1

Jan 9, 2017 6:30 PM in response to labeck

Did you end up having success with 2 x 8 GB? The support guy from OWC spent a lot of time with me trying to trouble shoot the new RAM but when I asked about that he said that their 2 x 8GB is not compatible with the mid 2010 27" iMac

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Answer 2

Jan 9, 2017 10:35 PM in response to labeck

You need the low density memory chips, the newer high density are causing the problems.

Memory comes in two configurations, one of which is the older kind: the ones that have 8 chips on each side (256x8), and the newer config ones with 4 chips on each side (512x8). The 512x8 config is too high-density for this model of iMac. The "8 chips on each side" ones are the ones needed....

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Answer 3

Sep 22, 2010 3:50 PM in response to labeck

I have a Mid 2010 iMac that was ordered with two modules of 4GB ram. After reading about problems upgrading to 16 GB I decided to go with "Apple Factory Original" memory modules available from www.MacRamDirect.com as suggested by another forum member.

All four of my slots are occupied with 4 GB ram modules and I have no memory issues. According to System Profiler the two original and the two new modules have the same part number.

Here is a link to the Apple Factory Original memory:
http://macramdirect.com/imac.html#im0

It costs around 20% more than non-Apple memory.

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Answer 4

labeck Author

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Sep 22, 2010 4:50 PM in response to OrangeKid

Thanks for the info, so far my crucial 8gb kits are working fine. Its only been 24 hours though.

Message was edited by: labeck

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Answer 5

labeck Author

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Sep 22, 2010 4:50 PM in response to OrangeKid

How long have you had it installed?

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Answer 6

normal1

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Sep 22, 2010 10:32 PM in response to labeck

I have been having a random shut down problem with my new iMac since day one. It also has 16GB of RAM installed, and I have tried a number of trouble shooting techniques to try and resolve this very annoying problem. None of them have worked so far.. At this time I have not resorted to removing all my third party RAM and reinstalling the 4GB which came pre installed form Apple.
Having been to a number of other forums, it would appear that this problem is being experienced by a quite a number of other new iMac users.
I have had it returned and looked at by an Apple technician who did not find any apparent problem with my machine. Most annoying problem as it s quite random.
I only hope that Apple are now aware of this problem and have a fix in the wings..

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Answer 7

Sep 23, 2010 7:41 AM in response to labeck

Hi labeck,
I have experienced the same issues with 16 G of OWC ram. I am now testing some things out.
See my thread on this : http://discussions.apple.com/thread.jspa?messageID=12231761#12231761

peterwillem

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Answer 8

labeck Author

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Sep 23, 2010 8:26 AM in response to peterwillem

I just read through your thread. I've had two 8gb kits of crucial memory (16gb total) installed in my machine for 48 hours and no problems. This is my fourth set of 16gb ram, the first three were from OWC and all caused random shutdowns. Since everyone that is having an issue with RAM bought it from OWC, its very possible that there new RAM for the mid 2010 iMac's is faulty.

But with my issue, the random shutdowns dont occur for at least 2-3 days, so the next 24-48 hours will be the real test. I'll report back what happens.

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Answer 9

Sep 23, 2010 8:45 AM in response to labeck

Thx,
I have tested 2 kits of 4 G OWC ram. No problems. I am testing the other 2 kits 4G OWC ram. If there is also no problem than the OWC ram should be ok.
And if I put 4 x 4 G kits of OWC ram back into the computer and the problems are returning than it is either the ram slot closest to the screen or the fact that this iMac can not handle 16 G of ram.
I could rule out the ram slot issue if I put only 2 kits of (tested) 4G OWC ram into the slot closest to the screen. But I am not sure if that will work, because it is contrary as what the manual says about installing ram.
I will come back to this when I have finished the testing period ( one week from now).

Did you install those 2 kits of 8G crucial ram into the slots the farthest away from the screen, like it says in the manual or into the ones closest to the screen?

peterwillem

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Answer 10

Sep 23, 2010 9:18 AM in response to labeck

I have had the iMac for 8 days. I ran it 24/7 for the first week with the Apple installed 8 GB memory in the slots furthest from the screen to make sure there were no problems. I installed the 8GB MacRamDirect memory after a week in the slots nearest the screen for a total of 16 GB and its been running for 24 hours without any issues.

In my previous reads I didn't pay enough attention to the fact that some memory issues start after several days. I'll report back after the iMac has run 24/7 for a week.

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Answer 11

labeck Author

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13 points

Sep 24, 2010 6:29 AM in response to labeck

Update: Crucial memory has also caused my iMAc to shutdown. It took 3 days as usual and it shutdown. Its definitely a problem with the iMac, I've been through 4 sets of memory and all have done the same thing.

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Answer 12

Sep 24, 2010 6:44 AM in response to labeck

Could it be the ram bank closest to the screen? Or did you already try that with a good,tested set of 8 G ram leaving the other bank open?
I am still in my testing period of the last pair of 8 G OWC ram in the bank farthest from the screen.
Nothing so far but than it is only a day since.

peterwillem

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Answer 13

labeck Author

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13 points

Sep 24, 2010 8:41 AM in response to peterwillem

I'm sure its not the slots, there is something wrong with the firmware or software. It simply does not like when 16gb of ram is installed.

I've called apple and requested a refund, I'm not paying $2500 for something that does not work as advertised. I hope they refund it, its been right at 30 days. I want to get a mac pro and be done with it.

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Answer 14

Sep 24, 2010 10:34 AM in response to labeck

ok, maybe you are right. I think I am going to poll on this forum if there people whose iMac i5/i7 mid 2010 can work with 16 G ram and whom have problems with it.

peterwillem

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Answer 15

labeck Author

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Sep 24, 2010 11:56 AM in response to peterwillem

where did your poll post go?

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