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

It ALWAYS took my machine 2-3 days to show the problem. My last test was with Crucial's 8gb kits, it worked well for three days then crapped out. Its going back, the iMac that is.

I've been fine running 12 gigs. I'm taking it in to apple tomorrow for them to look at it as requested by a senior apple advisor.. We'll see what happens..

I agree with your final outcome of this issue.
But , for me, it does not solve the problem. I am stuck with 16 Gig of OWC ram, of which I can only use half.
RMA it to OWC and ask for refund will cost me a lot of extra money. (transport by Fed Ex= $130,- and vat and import duties another $130,-) .
Not to mention the buying of 20% more expensive Apple ram.
So I have to think about this if all that extra money is worth it, moreover because I really don't need all the 16 G of ram. For me it was more a matter of having, a expensive one as it turned out to be.
So for this moment I find it hardly except able that Companies like Apple and OWC put me into this spot in the first place. Both should do something about it. But I am realistic enough to realize that that will take a long time, if at all.

peterwillem

Thx,
I will look into that tomorrow. Meanwhile I have put 16 G of OWC ram in the iMac and within 7 hours I had the problem again.
I am trying one last option with the 16 G ram inside, and that is working OSX SL in the 64 bit mode.
That is supposed to make no difference but I want to make sure that that really is true.

peterwillem

As I expected the 64 bit mode did help either


quote: 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.

Well the OWC rams I have are made of 8 chipsets each side, just like the Apple rams Hynix&Samsung.
So the 8 and 4 are not the cause of the problem, I would say.

I am going to discuss this with OWC and see if I can do some trade, but I want to be sure that the Samsung 16 GB will solve the problem.


peterwillem


peterwillem

Well I have just a few hours ago installed 2 x 4 G of OWC ram and 2 x 2 G Apple ram.
So far no problems, but it is early days.
In one bank a 4G and a 2 G ram , will that work? Aside from the sudden shutdown issue.
I always thought that the rams in one bank should be equal in size.

Anyhow I will await the outcome of my present set up.


peter willem

The RAM in the two top slots (closest to the screen) should match, and the RAM in the two bottom slots should match. The banks (as displayed in the System Profiler) correspond to right side and left side. It is confusing. I would put the Apple RAM in the top slots.
Probably the best design would be 2 rows of 3 banks for this chip. But they have probably figured out some other way to get three memory paths out of the banks.

Ok,
so what mcsys suggested, 3 x 4 G ram and 2x2 G ram will not work, because that means 2 different rams in the 2 lower slots. Right?

peter willem

I have sent a mail about this problem to OWC.I like to quote OWC reaction to my mail:

Hello,

+OWC has tested the ram in multiple iMacs of this group and the machines work fine with 16 gb of ram.+

XXXXXXXX
+Technical Customer Service Representative+
+Other World Computing, Inc. (OWC)+
+OWC.net, Inc.+

So how come that so many of us have problems with that same ram? What is going on?
Hope that somebody fromApple or OWC van shed some light on this.
I obviously X'ed the name of the person in the mail.
peter willem