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jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
Hey,

so I bought my iMac a week ago and have been having a bit of trouble with it. Everytime I put 32GB of RAM into it, it randomly crashes (kernel panic).

At first I had Kingston HyperX RAM which I returned, now I am using crucial (bought directly from crucial) and having the same issues.

I've also stumbled upon others on the apple discussion boards and crucial forums.

So just wanted to check is anyone else having these issues? Also, is anyone having these issues after buying an iMac with 32GB direct from Apple?
 

DOlsson

macrumors member
Feb 3, 2007
90
0
Are each of the 4 modules the exact same brand?

Did you buy them in pairs by chance, like two packs of two? Not sure that this totally matters, but just curious/weeding out a few things.

What about ram timings? Do you know what they're rated at? What about the speed, are they all PC3-12800?

Are you certain that they meet all of the requirements listed here? Late 2013 iMac Ram Specifications
(Again, this is basic stuff, don't get mad - just getting more information).

I have a late 2013 Haswell iMac and I've got two 8GB modules installed, but it's the Apple brand. No issues, but then again, that doesn't mean anything.
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
Are each of the 4 modules the exact same brand?

Did you buy them in pairs by chance, like two packs of two? Not sure that this totally matters, but just curious/weeding out a few things.

What about ram timings? Do you know what they're rated at? What about the speed, are they all PC3-12800?

Are you certain that they meet all of the requirements listed here? Late 2013 iMac Ram Specifications
(Again, this is basic stuff, don't get mad - just getting more information).

I have a late 2013 Haswell iMac and I've got two 8GB modules installed, but it's the Apple brand. No issues, but then again, that doesn't mean anything.

Hey,

i've tried 2 packs of 16GB (2 x 8GB) Kingston DDR3 1.5v CL9 PC3012800 1600mhz and had problems. Wasn't sure if it was to do with the CL rating/voltage or a bad stick.

I sent it back and went to crucial (direct not via another retailer) and have bought 2 packs of 16GB (2 x 8 GB) Crucial RAM 1600mhz CL11 1.35v. All modules are the same, showing up exactly the same in System information and status is OK for all.

Experiencing the same issues. The annoying thing is that it only happens after a few hours of use and is difficult to reproduce.

As far as i'm aware it meets all the requirements on the list (I doubt crucial would say 100% Mac Compatible if it wasn't as their return rates would be through the roof).

Again, I have found a few others who seem to have it as an issue but only when using 32GB RAM :-/
 

DOlsson

macrumors member
Feb 3, 2007
90
0
Very interesting... I'm not sure what may be up. Especially since you're not using the 1.5v ram now. Not that I know for certain this causes an issue, but some people on this thread have mentioned that the 1.5v ram will cause issues after a few hours of usage (again, I have no thoughts on this, just providing info - this thread)

Here's a test, the ram that originally came with the machine - do you still have it? Put that stuff back in, and only that ram. Then do your thing for a while, put a load on the computer, really work it.

Were there any crashes?

I'm hoping the answer is yes - meaning your new memory is not the issue, but maybe something else.

If the answer is no... Them hmm... One other thing you could try is returning your crucial memory, and getting pure Apple certified memory straight from Apple. This may be silly, and more expensive - but maybe it's worth a shot?

I feel your frustrations my friend, this would be driving me mental.



Hey,

i've tried 2 packs of 16GB (2 x 8GB) Kingston DDR3 1.5v CL9 PC3012800 1600mhz and had problems. Wasn't sure if it was to do with the CL rating/voltage or a bad stick.

I sent it back and went to crucial (direct not via another retailer) and have bought 2 packs of 16GB (2 x 8 GB) Crucial RAM 1600mhz CL11 1.35v. All modules are the same, showing up exactly the same in System information and status is OK for all.

Experiencing the same issues. The annoying thing is that it only happens after a few hours of use and is difficult to reproduce.

As far as i'm aware it meets all the requirements on the list (I doubt crucial would say 100% Mac Compatible if it wasn't as their return rates would be through the roof).

Again, I have found a few others who seem to have it as an issue but only when using 32GB RAM :-/
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
Very interesting... I'm not sure what may be up. Especially since you're not using the 1.5v ram now. Not that I know for certain this causes an issue, but some people on this thread have mentioned that the 1.5v ram will cause issues after a few hours of usage (again, I have no thoughts on this, just providing info - this thread)

Here's a test, the ram that originally came with the machine - do you still have it? Put that stuff back in, and only that ram. Then do your thing for a while, put a load on the computer, really work it.

Were there any crashes?

I'm hoping the answer is yes - meaning your new memory is not the issue, but maybe something else.

If the answer is no... Them hmm... One other thing you could try is returning your crucial memory, and getting pure Apple certified memory straight from Apple. This may be silly, and more expensive - but maybe it's worth a shot?

I feel your frustrations my friend, this would be driving me mental.

As far as I can tell, no crashes with the original RAM (though I only ran it for a day) but usually I get 1-2 crashes per day.
 

ragtop232

macrumors newbie
Dec 2, 2012
10
0
I can unequivocally recommend Kingston HyperX. I just upgraded my late 2013 iMac with 32gb of Kingston HyperX 16GB Kit 1866MHz DDR3 PC3-14900 Non-ECC CL11 1.35V Low Voltage. Here is the link to Amazon Kingston HyperX Memory.

Another benefit is this RAM is running in my iMac @1867MHz. It also fits the slots perfectly.
 

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ragtop232

macrumors newbie
Dec 2, 2012
10
0
So, the new iMac supports 1867 MHz RAM? :confused:

It does. As you can see from the screen shot, it actually reports the speed accurately as well. I've monitored memory temps via iStat Menu's and have never went over 36-C. Most of the time all four bays idle at 28-C.

Jim
 

MacsRgr8

macrumors G3
Sep 8, 2002
8,284
1,753
The Netherlands
It does. As you can see from the screen shot, it actually reports the speed accurately as well. I've monitored memory temps via iStat Menu's and have never went over 36-C. Most of the time all four bays idle at 28-C.

Jim

Of course it does. The chipset on the motherboard supports it.

Cool.
Then why isn't it mentioned on Apple's website, and, why aren't they standard delivered which the faster RAM?
Is it to differentiate the new Mac Pro more?
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
I wonder if I have just been unlucky enough to get bad ram twice from two different brands?

I am still getting kernel panics after another clean install... I have a bunch of crash reports if anyone on here can interpret them... I'd be very grateful :)

Only have a week left before my 14 days since delivery are up with apple so I may return it :-/
 

cpc6128

macrumors member
Oct 24, 2013
46
0
As mentioned in another thread - My new iMac is also crashing with 32gb.

I have the Corsair Vengeance 8GB Sticks x 4 (model CMSX8GX3M1A1600C10 / CMSX16GX3M2A1600C10)

It was running really well until a couple of hours of gaming it just froze with a kernel panic message.

I am currently running it with the original 1.35v ram and so far it is not crashing.

Could this be something can Apple can fix with a firmware? The ram meets all requirements on the Apple support page.
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
As mentioned in another thread - My new iMac is also crashing with 32gb.

I have the Corsair Vengeance 8GB Sticks x 4 (model CMSX8GX3M1A1600C10 / CMSX16GX3M2A1600C10)

It was running really well until a couple of hours of gaming it just froze with a kernel panic message.

I am currently running it with the original 1.35v ram and so far it is not crashing.

Could this be something can Apple can fix with a firmware? The ram meets all requirements on the Apple support page.

I too have switched back to the stock RAM to see if I can make it crash.

From what I have witnessed so far, it only happens when I have four modules in (I can use two modules of Third Party RAM fine but as soon as all the dimm slots are used it will randomly panic).

My Kernel panics are really sporadic... machine starts fine but they happen anywhere between 1hr and 12 hours of use which is making diagnosing it a b*tch.

I am going to try for a few more days and if I can't work out what it is, the iMac and the 3rd party ram are going back and I am going to hold out on my MBP a little longer.
 

richard13

macrumors 6502a
Aug 1, 2008
835
197
Odessa, FL
I too have switched back to the stock RAM to see if I can make it crash.

From what I have witnessed so far, it only happens when I have four modules in (I can use two modules of Third Party RAM fine but as soon as all the dimm slots are used it will randomly panic).

My Kernel panics are really sporadic... machine starts fine but they happen anywhere between 1hr and 12 hours of use which is making diagnosing it a b*tch.

I am going to try for a few more days and if I can't work out what it is, the iMac and the 3rd party ram are going back and I am going to hold out on my MBP a little longer.

You say "anywhere between 1hr and 12 hours" is there a difference in how you are using your iMac? Like, does it takes 1 hour if you are running some intensive app(s) but 12 hours idling?

I ask because I ordered my new iMac with 8GB of RAM but intend on maxing it out and I'd like to know how I can test to ensure the system is stable with all 4 slots filled.
 

IA64

macrumors 6502a
Nov 8, 2013
552
66
As mentioned in another thread - My new iMac is also crashing with 32gb.

I have the Corsair Vengeance 8GB Sticks x 4 (model CMSX8GX3M1A1600C10 / CMSX16GX3M2A1600C10)

It was running really well until a couple of hours of gaming it just froze with a kernel panic message.

I am currently running it with the original 1.35v ram and so far it is not crashing.

Could this be something can Apple can fix with a firmware? The ram meets all requirements on the Apple support page.

The CMSX8GX3M1A1600C10 is rated at 1.5V. How are you running it @ 1.35V?

On the specs sheet it clearly says : If your notebook uses a 4th Generation Intel Core processor, you should use one of our 1.35 Volt Vengeance memory kits.
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
You say "anywhere between 1hr and 12 hours" is there a difference in how you are using your iMac? Like, does it takes 1 hour if you are running some intensive app(s) but 12 hours idling?

I ask because I ordered my new iMac with 8GB of RAM but intend on maxing it out and I'd like to know how I can test to ensure the system is stable with all 4 slots filled.

To be honest, not really. Yesterday I worked in illustrator a bit (not too intense, wasn't a massive file) also listened to some music and all was well from 11AM until about 6PM. I put the machine to sleep and at around 9.30PM I started using chrome and iTunes then it just randomly cut out.

It got delivered last Thursday and I have had about 10-12 random restarts with the "your computer restarted because of a problem" message. Going absolutely crazy with it now. Apple Chat Adviser pretty much told me to take out the third party ram and try with Apple's ram. I tried explaining I only have 2x4GB of the apple RAM and the issue only occurs with 4 sticks of RAM in (I can use any combination of 2 sticks without a crash, but as soon as 4 are in the random restarts continue).

I am wondering if it's either a firmware/software issue with OSX (though I am on a clean 10.9 install and I have seen others with the same problem on 10.8.5), a conflicting third party software issue or faulty RAM (though it did the same thing with the RAM I had before this).

At the moment I am back on Apple's 2x4GB sticks and the moment it crashes I am calling Apple and it is going back. I need a new machine for work but at the moment working on my 5 year old MBP with a 15" screen is more productive.

If anyone is good at interpreting crash reports I would appreciate it if you would take a look at these: https://discussions.apple.com/thread/5532729

Also to anyone who has experienced crashes, are you running any of the following?

- Adobe Products/Creative Cloud
- Wacom Tablet
- Magic Trackpad rather than mouse
 

drambuie

macrumors 6502a
Feb 16, 2010
751
1
So, the new iMac supports 1867 MHz RAM? :confused:

Its not the iMac that supports the RAM at that speed, its the 4th generation Core i CPU's on chip memory controller. There are no other circuit components between the CPU and RAM sockets. If you're using XMP DIMMs and the CPU supports the rated speed, it will clock the RAM at that speed. The Kingston HyperX is XMP.

If the CPU only supported a max speed of 1600MHz, the 1866MHz RAM would be clocked at that speed, but with a CL of 9 rather than 11, so there would still be a performance gain over the original Apple RAM.
 

cpc6128

macrumors member
Oct 24, 2013
46
0
The CMSX8GX3M1A1600C10 is rated at 1.5V. How are you running it @ 1.35V?

On the specs sheet it clearly says : If your notebook uses a 4th Generation Intel Core processor, you should use one of our 1.35 Volt Vengeance memory kits.

The apple site clearly doesn't state it must be a DDR3L/1.35v and the Vengeance ram meets the criteria listed. Others have reported this ram works fine in the Haswell iMac but I wonder if they have ran their iMac long enough like I did to experience the KP..

Currently my iMac is not crashing at all on the original 2x4gb sticks. I am not going to bother with the Vengeance ram anymore.
 

jordanm86

macrumors regular
Original poster
Oct 21, 2011
231
52
The apple site clearly doesn't state it must be a DDR3L/1.35v and the Vengeance ram meets the criteria listed. Others have reported this ram works fine in the Haswell iMac but I wonder if they have ran their iMac long enough like I did to experience the KP..

Currently my iMac is not crashing at all on the original 2x4gb sticks. I am not going to bother with the Vengeance ram anymore.

I agree, the Apple memory specifications makes no specifications on the RAM with regards to voltage - it's very misleading.

I have just run 2 memtests on my Crucial 1.35v DDR3 RAM and it came back all ok. Is it possible for a memory test to get it wrong? If not, is it likely I have another hardware fault in my iMac or perhaps even just a software related issue?
 

cpc6128

macrumors member
Oct 24, 2013
46
0
I agree, the Apple memory specifications makes no specifications on the RAM with regards to voltage - it's very misleading.

I have just run 2 memtests on my Crucial 1.35v DDR3 RAM and it came back all ok. Is it possible for a memory test to get it wrong? If not, is it likely I have another hardware fault in my iMac or perhaps even just a software related issue?

I ran hardware test and memtest non stop on the Vengeance and returned no issues whatsoever. Felt confident that all is ok then the sudden crash couple of hours into playing Sim City.

I think people here with iMacs loaded with 32gb 1.5v ram will need to run their iMac for a few hours at least to see it happen.
 

IA64

macrumors 6502a
Nov 8, 2013
552
66
The apple site clearly doesn't state it must be a DDR3L/1.35v and the Vengeance ram meets the criteria listed. Others have reported this ram works fine in the Haswell iMac but I wonder if they have ran their iMac long enough like I did to experience the KP..

Currently my iMac is not crashing at all on the original 2x4gb sticks. I am not going to bother with the Vengeance ram anymore.

Every RAM manufacter is selling 1.35V mac compatible memory modules for late 2013 models.

Moreoever, late 2013 iMac comes with DDR3L RAM.

Considence ? Please...

Apple should update the list of memory specs requirement.
 
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