Problem with 16GB on 2010 iMac 27" i5 & i7.

Question

Level 1

3 points

Problem with 16GB on 2010 iMac 27" i5 & i7.

I've 8 X 4GB 1333Mhz DDR3 RAM, latest 2010 iMac i5 & i7.
Trying to install 16GB on each iMac.

1. Both work well with 2X2GB.
2. After installing 4 X 4GB RAM , they freeze, cursor spinning ball or kernel panic within 10 to 15mins.
3. Removed all RAMs & installed another batch of 4X4GB, same problem.
4. Installed 2 X 4GB RAMs, they work well.
5. Repeat step 4 with the rest of the 6 pieces of 4GB, they work well with 8GB.
6. Also tested with 4 X 2GB, they work well.

I can only conclude that the new 2010 iMac 27" does not support 16GB well. No doubt it recognizes 16GB at "About This Mac" but it freezes after 15mins. I suspect is due the firmware issue.

Anyone else have the same issue?

Found similar problem at http://discussions.apple.com/thread.jspa?threadID=2567543&tstart=15

MacBook Pro, Mac OS X (10.6.4), iMac

Posted on Sep 4, 2010 3:13 AM

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Answer 1

den.thed

Level 10

90,868 points

Sep 4, 2010 7:03 AM in response to mcsys

Hello mcsys

Not all third party RAM works in an iMac, who is the manufacture and what are the full spec's?

Does that RAM meet all of these criteria?

PC3-8500
Unbuffered
Nonparity
204-pin
+1066 MHz+
+DDR3 SDRAM+

But as important, RAM with the following features *_will not work_* in an iMac's.

+Registers or buffers+
PLLs
ECC
Parity
+EDO RAM+

See > http://support.apple.com/kb/HT3918

Dennis

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Answer 2

mcsys Author

Level 1

3 points

Sep 4, 2010 8:13 PM in response to den.thed

l'm not avoiding your questions but just lack of information. I forwarded the questions to my local vendor & now waiting for their reply.

I should check the link at http://support.apple.com/kb/HT4255 not HT3918
& the RAM criteria should be

PC3-10600
Unbuffered
Nonparity
204-pin
1333 Mhz
DDR3 SDRAM

For sure the RAMs are PC3-10600,204-pin 1333Mhz DDR3 SDRAM.
But I can't tell whether they are unbuffered & nonparty.

I knew about OWC memory but I can't convince myself that the new iMac 2010 will work with 16GB properly unless someone here tested it.

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Answer 3

mcsys Author

Level 1

3 points

Sep 10, 2010 11:34 PM in response to TheAnimist

TheAnimist got iMac 27" i7 with 16GB (RAM from OWC) having problem.
Why are you having 2 X 8GB?
I thought the RAMs suppose to be 4 X 4GB.?

To answer den.thed question.
Who is the manufacture and what are the full spec's?

Reply from my local vendor:
Generic brand.
RAM meets all criteria
PC3-10600
Unbuffered
Nonparity
204-pin
1333 MHz
DDR3 SDRAM

According to
http://discussions.apple.com/thread.jspa?threadID=2548180&tstart=150

Sjohnson803 got iMac 27" i7 2010 with 16GB (RAM from OWC) having problem.
Currently, RAM down to 12GB without problem.

Jeff.C got iMac 27" i7 2010 with 16GB (RAM from OWC) having problem.
Not sure his problem has solved.

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Answer 4

mcsys Author

Level 1

3 points

Sep 20, 2010 8:12 AM in response to TheAnimist

Update…
Some data collected from
http://discussions.apple.com/thread.jspa?threadID=2548180&tstart=150

Most users solved their problem by downgrading the RAM to less than 16GB.

Having problem with 16GB on 2010 iMac 27", downgrade ok.
1. myself, mcsys - i5, i7, i7 8GB - OK
2. Sjohnson803 - i7 12GB - OK
3. Jeff.C - i7 8GB - OK
4. TheAnimist - i7 8GB - OK
5. tck49 - i5 12GB - OK
6. myror - unknown

OK with 16GB on 2010 iMac 27"
1. TheAnimist - i7

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Answer 5

mcsys Author

Level 1

3 points

Sep 30, 2010 10:49 AM in response to peterwillem

I've 2 different sets of Apple Original 2GB DDR 1333Mhz RAMs that were pulled out from iMac 11,3, They are made of Hynix Chips & Samsung Chips. The Hynix chipsets are similar to Transcend RAM & Samsung chipsets are similar to http://eshop.macsales.com/item/Other%20World%20Computing/1333SAM3S4GB/.
The RAMs are all made of 8 chipsets on each side

With reference from labeck's thread, http://discussions.apple.com/thread.jspa?threadID=2588800&start=0&tstart=15
,he bought from OWC & Crucial

OWC
http://eshop.macsales.com/item/Other%20World%20Computing/1333DDR3S16S/
Crucial
http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=769226C4A5CA7304

From the URLs, I see the RAMs are made of 4 chipsets on each side. I'm not sure whether that is the reason behind it. Crucial RAM is made of Micron chips. No clue what chipsets are used for OWC as sticker pasted on them.

I suggest you ask to trade off your problematic RAMs & top up to get 4 X OWC 4GB Samsung Factory Original DDR3 PC3-10600 instead.

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Answer 6

Oct 4, 2010 10:41 AM in response to mcsys

Since I won't be able to use the16G OWC ram for a while, I am interested in this matter. Presently I am running 12 Gig. 2 x 4 G OWC and 2 x 2 Apple ram. Works good.
Should I replace one of the apple ram with one OWC ram in the lower slots in order to get more performance? Or will that have the opposite effect?
see this thread, though it concerns an end 2009 type iMac.
http://discussions.apple.com/thread.jspa?threadID=2308302&tstart=0

peterwillem

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Answer 7

Jeff.C

Level 1

14 points

Oct 22, 2010 10:46 AM in response to mcsys

This is just a small update on my current status.

So a few weeks ago I received new RAM from OWC (RMA'd). It ran fine for about 7-8 days and then crashed 4 times in two days.

My case has been on-going with the Apple engineers for some time now. After reviewing some of my system logs they told me not to use a custom name for my primary HDD and to rename it back to "Macintosh HD" (renaming any other HDDs is not a problem). They claim that Adobe Flash has known issues if you rename your primary boot HDD. I'm not sure how that has anything to do with using 16GB or RAM, but I'm willing to try anything. So far since I've renamed it back to "Macintosh HD" I haven't had any issues for at least 4 days, but I'm not holding my breath on this one (they weren't too sure either, but they want to eliminate it as a possible culprit, so I'm game).

Just out of curiosity, has anyone else who has renamed their primary HD been having this same issue?

--
In case anyone is interested, the Apple engineers have been following the below threads I gave them last month:
http://discussions.apple.com/thread.jspa?threadID=2567907 (this one)
http://discussions.apple.com/thread.jspa?threadID=2588800
http://discussions.apple.com/thread.jspa?threadID=2560826
http://discussions.apple.com/thread.jspa?threadID=2548180

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Answer 8

Oct 23, 2010 11:08 AM in response to apple_enthusiast

Here is the link to that post by Atkinstorefron.
http://discussions.apple.com/thread.jspa?threadID=2588800&start=15&tstart=0

It says somewhere that he uses everything including the ram from the Apple store.

I still like to know if somebody can do my proposed test, written in a post before?

peterwillem

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Answer 9

Jeff.C

Level 1

14 points

Jan 19, 2011 8:11 AM in response to peterwillem

UPDATE:

A user by the name of Gianfri has confirmed that OWC recently "tweaked" their RAM to address the issue.

reference: http://discussions.apple.com/thread.jspa?threadID=2548180 (see near bottom of page 13 in that thread for the comment from user Gianfri).

For those still having the problem (with OWC RAM), I'd suggest contacting them to get the RAM replaced (OWC gives lifetime warranty on their RAM, so they'll replace it).

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Answer 10

babowa

Level 9

78,556 points

Sep 24, 2011 8:20 AM in response to petran81

I've not heard of any problems with Hynix RAM (which is the same brand Apple has been using, so:

did you seat the RAM correctly (all of them)?

do all 4 modules show up in System Profiler as ok?

have you tried eliminating one by one to see if there might be a problem with one of them?

And, I had a problem with one of my RAM slots on my Macbook - it was the slot, not the RAM that was causing the problem, so does one of your four slots feel or react different when trying to seat the RAM?

And, you might want to run Apple Hardware Test:

http://support.apple.com/kb/HT1509

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Answer 11

babowa

Level 9

78,556 points

Feb 18, 2012 9:59 AM in response to Jonathan Mortimer

The point of this thread was the problem that the Macs did not work with 16 GB third party RAM; it had nothing to do with the RAM specs. That problem was addressed some time ago with OWC working with Apple.

I would trust Apple's and everymac.com's RAM specs any day (these should be yours if I picked the right 11,1 model):

http://support.apple.com/kb/SP576

http://www.everymac.com/systems/apple/imac/stats/imac-core-i7-2.8-27-inch-alumin um-late-2009-specs.html

And, out of curiosity, why are you resurrecting several old threads (one being more than 6 months old)?

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Answer 12

mcsys Author

Level 1

3 points

Sep 4, 2010 8:05 AM in response to den.thed

Hi Dennis,

8GB (2X4GB) or (4X2GB) RAMs work well on both iMac i5 & i7. I've tested for a week.

The problem only occurred when I installed (4X4GB) 16GB to both set.

If those RAMs are not compatible, then the problem should appear on 8GB too.

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Answer 13

den.thed

Level 10

90,868 points

Sep 4, 2010 8:56 AM in response to mcsys

Why do you avoid the questions?

{quote:} who is the manufacture and what are the full spec's?{quote}

If it is not working together in sets of 4, then there is something wrong with the RAM and you need to contact the vendor for an exchange or return.

Maybe try OWC, there RAM is Mac tested:
http://eshop.macsales.com/shop/memory/iMac/2010/DDR321.527

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Answer 14

Sep 8, 2010 11:45 PM in response to mcsys

Hi,

I'm having the same problem.

I have 2 x 8.0GB (2x4.0GB Kit) PC3-10600 DDR3 1333MHz SO-DIMM 204 Pin CL9 SO-DIMM Memory Upgrade Kit for Mid 2010 21.5" & 27" iMac Models from OWC.

I get the exact same issues, apple logo at boot then a hung spinner prior to the OS loading, one time the OS loaded and the about this mac showed 16GB, but after a varying number of minutes the same panic/crash.

I also get weird striping colours at boot time and various kernel panic errors.

I've gone through the same process, less memory no problem, but all four and a nightmare...

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Answer 15

labeck

Level 1

19 points

Sep 20, 2010 12:18 PM in response to TheAnimist

I'm curious, the 2-8gb kits that you have that work, were they directly from Crucial? I just ordered two 8gb kits from gem and I hope it works. My two 16gb kits from owc made my machine crash, not sure if it's the imac or the ram, hoping it's the ram.

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