iMac 5K stock + OWC RAM issue

[K3mp]

Hi all,

Over the summer I picked up a 5k iMac with 8GB of RAM. After about a month or so of "making due" with 8 GB, I went ahead and purchased an additional 32 GB of RAM for OWC. I installed the RAM in addition to the stock RAM, and have experienced kernel panics when awaking from sleep, or I will find that it kernel panicked while it was asleep for some time. Due to the common (but not always) kernel panics, I have removed the stock RAM for the time being. I could work with 32 GB fine, I am just concerned if there is another issue lurking somewhere.

My question is: is this common behavior? I did some googling, and found older thread saying mixing RAM manufacturers could cause issues, as well as threads saying it should work fine.

Any input?

 

[mikehalloran]

Mismatching pairs of RAM on an iMac will not cause your problem as long as they are installed properly.

It is possible to do it wrong and cause problems. This page has a good discussion:
https://www.ifixit.com/Answers/View/223429/How+to+couple+RAM+Modules+in+iMac+27


You are not crystal clear on if you bought a pair of 16G sticks or 4 8G. It does appear more likely that you bought only 2.

If you bought 2 sticks only and they're larger than the stock RAM, there is no way to ID the bad stick—fortunately, you don't need to with OWC.

The only test you can run is to swap the OWC RAM with the stock. If only one pair gives you problems, you know the culprit. If now, everything is fine with both pairs, there's a chance that you didn't seat the RAM properly (almost impossible but...).

If the OWC RAM, get an RMA and send it back. They're very good about this.

 

[K3mp]

Right now, for the sake of experimentation, I'm running just the 32GB (16 GB x 2). If no problems arise, I will re introduce the Apple RAM. Thanks for the response, I had questioned the RAM seating as being an issue, and have checked to see if they were snug in the past. Maybe they just needed to be removed then re installed.

 

[MacKarmaTech]

Right now, for the sake of experimentation, I'm running just the 32GB (16 GB x 2). If no problems arise, I will re introduce the Apple RAM. Thanks for the response, I had questioned the RAM seating as being an issue, and have checked to see if they were snug in the past. Maybe they just needed to be removed then re installed.

 

[mikehalloran]

Yea, sure.

Before I'd read that article, I figured that RAM in the wrong banks wouldn't boot an iMac (certainly not my 2010–2011s). Apparently it will with the late ones which is why I threw that in.

Learn something new now and then...

 

[MacKarmaTech]

I work as a freelance Mac Tech and all I can say is that I have run into countless 'issues' with OWC's memory (also with their NVMe drive options as well). I know that their are many others here that haven't encountered these types of OWC branded memory related problems, but in my personal experience, I've had more than my share of "bad ram" modules purchased from them. For that reason, I now never recommend purchasing OWC's memory (or SSD's and/or NVMe drives) due to their higher than retail failure rates. Besides, you can buy high quality, brand name Crucial or Corsair memory modules for usually less than the premium price OWC charges for their "no name" brand.

Just my future buying advice and anecdotal opinion.


P.S.: Never, ever buy one of their 'ad hock' NVMe drive related anything. I've had to return several because of their propensity to either arrive DOA, or they tend to fail shortly thereafter - mainly due to OWC using lower quality Sandforce controllers.

 

[mikehalloran]

Well, I live near (insert large Silicon Valley Memory vender here) so, while I've had to make OWC come through on warranty (3x in 30 years, I think), I know that there's worse and I won't drive there.

There are a couple of L.A. based Crucial and Kingston vendors I use but OWC is fast and customer service is excellent.

Never, ever buy one of their 'ad hock' NVMe drive related anything. I've had to return several because of their propensity to either arrive DOA, or they tend to fail shortly thereafter - mainly due to OWC using lower quality Sandforce controllers.

No argument there. Besides, the prices are way too high.