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2020 iMac constant crash with 128gb RAM
- Thread starter frysteen
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I got my 128GB OWC kit in today. For some reason. I had to install 64GB boot it. Then install the 2nd 64GB and everything has been running smooth all day.
The iMac went for hours or even days without crashing, but it did eventually. I completely shut it down each night and start it every morning. It has happened randomly. By the way, I removed two of the modules and it has been working just fine (no crashes) for over a week now. For some reason, using all four OWC memory modules leads to random crashes. This is 4x16GB modules by the way.
Got a new iMac 2020 i9 10-Core with 5700 XT when it came out. 8 GB Ram from apple which I then upgraded with 4 32gb sticks from OWC. I ordered from Amazon and my Mac would crash every other hour. I narrowed it down to bad ram. I sent it back to amazon and bought same 128GB from OWC and it performed much better. BUT Then it would crash when apps like Folding@Home would run and turn up the CPU's, same would happen when running photoshop, very random. The annoying part is that my old iMac 2012 would never do that.
THEN, thanks to this thread. I took out a 32gb stick (Top One), leaving a total of 96gb inside. Rebooted, machine reads 96gb at 2667 MHz and its been running solid since yesterday(Knocks on wood). With Folding@Home thrown in along a ton of other things in the background. It feels like I got my computer back.
PS. I tried EVERYTHING before doing this re-installed OS, booted in safe mode, unplugged all three hard drives and Wacom Cintiq 24in, and the crashes would still happen. Bummed I can't use 128gb, but not much of a difference from 96gb.
THEN, thanks to this thread. I took out a 32gb stick (Top One), leaving a total of 96gb inside. Rebooted, machine reads 96gb at 2667 MHz and its been running solid since yesterday(Knocks on wood). With Folding@Home thrown in along a ton of other things in the background. It feels like I got my computer back.
PS. I tried EVERYTHING before doing this re-installed OS, booted in safe mode, unplugged all three hard drives and Wacom Cintiq 24in, and the crashes would still happen. Bummed I can't use 128gb, but not much of a difference from 96gb.
As I mentioned above, I had the same "crash" issue with 4x16 GB of OWC memory. The iMac worked just fine with just two of the four memory modules installed, but not all four. I received replacement modules from OWC and they have been working just fine for a couple of weeks now with absolutely no crashes with all four modules installed. I am convinced that the memory I had received initially was defective.
The speed drop is because you are running with 3 modules. To maintain your geekbench score, either remove another module or switch to a different brand of memory that can handle 4 modules at once.
With all due respect, unmatched memory is not going to drop his geekbench score by some 30% (I'm assuming it went from something like 9000 down to 6500). The performance hit from not having a 4th stick would be a handful of percentage points.
He should definitely return the ram and get new sticks.
I have the same exact problem with the same exact setup except 8GB on the graphics card. Wish I had discovered this thread earlier as it's been maddening trying to figure this out. OWC doesn't know what it is either, but was willing to give a refund on the 2 RAM modules I couldn't use. If anyone figures out a fix or another RAM vendor that seems to work at 124GB would love to know. Thanks.
I know almost everyone on here is all "OWC is the greatest, bla bla bla..." but in my experience with their products over the years the quality of their ram and ssd's has always been spotty for me.
I know this will sound like heresy to some here, but I bought sticks of Corsair Vengeance ram for both my 2019 imacs (64gb each, 4 - 16gb ram sticks each) and it has been flawless and my benchmark scores are top notch.
So maybe OP should try sonething other than OWC next time.
In case you haven't yet discovered it, check out this Apple discussion forum. Quite a few 2020 iMac owners of the 10-core i9 model are experiencing similar problems. Look at the fourth page. Looks like the problem was resolved by replacing OWC RAM with Micron RAM. That thread may be right up your alley.
2020 iMac crashing often - Apple Community
Always wondered why people in these forums often buy OWC over the big trusted names, and often for a higher price. I think it’s because OWC advertises on Apple related sites a lot, but they’re basically an off-brand / generic brand. Their stuff is going to be lower quality.
Wouldnt surprise me. I'm not a big fan of the quality of OWC ram or ssd'sIn case you haven't yet discovered it, check out this Apple discussion forum. Quite a few 2020 iMac owners of the 10-core i9 model are experiencing similar problems. Look at the fourth page. Looks like the problem was resolved by replacing OWC RAM with Micron RAM. That thread may be right up your alley.
2020 iMac crashing often - Apple Community
discussions.apple.com
I had a similar problem. I removed the original Apple supplied RAM and use just the OWC - no crashes.
Confirming that a new set of 128gb Ram from OWC fixed my random crashes.
I ordered a set from Amazon back in October when I first purchased the new 2020 iMac and the crashes were really bad. I sent them back after reading it could be the ram, and read somewhere that buying ram from Amazon is a bad idea. Got refunded and bought directly from OWC. iMac still crashed, but much less. I took out one stick and left 96gb in there. The crashes disappeared BUT my performance took a massive hit. I sent them back to OWC, and they replaced them without a question. They also said this there was nothing wrong with them. BUT as soon as I installed this third set of 128gb RAM, I pushed my machine and no crashes. My performance is back up, Geekbench score of 10k+, and no crashes. Perhaps the first batches of ram from OWC had something going on with them.
I ordered a set from Amazon back in October when I first purchased the new 2020 iMac and the crashes were really bad. I sent them back after reading it could be the ram, and read somewhere that buying ram from Amazon is a bad idea. Got refunded and bought directly from OWC. iMac still crashed, but much less. I took out one stick and left 96gb in there. The crashes disappeared BUT my performance took a massive hit. I sent them back to OWC, and they replaced them without a question. They also said this there was nothing wrong with them. BUT as soon as I installed this third set of 128gb RAM, I pushed my machine and no crashes. My performance is back up, Geekbench score of 10k+, and no crashes. Perhaps the first batches of ram from OWC had something going on with them.
If I recall, a very long time ago macs used registered dram and PCs did not
that hasn’t been the case since the intel shift at least, but OWC has been a Mac parts supplier for a long time and people don’t do their research.
I'm having the same problem. A few weeks ago I bought pretty much the same machine: 2020 iMac, 3.6GH 10-core with AD Radeon 16GB graphics card. I too purchased and installed four OWC 32GB sticks. The crashing started when I was using Zoom - so I thought it was a Zoom problem. But I was just working on a Powerpoint presentation, and the same thing happened. iMac freezes (can't operate mouse, or anything), then shuts itself down.
Although this is obviously a self-serving piece, Crucial do make some points here worth thinking about:
www.crucial.com
I don't recall anyone having issues with four Crucial sticks
The Truth about Memory Manufacturers
Learn the difference between true memory manufacturing companies and organizations that only assemble the modules & why it's an important distinction.
I don't recall anyone having issues with four Crucial sticks
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So glad I found this thread, I also bought 4x32gb sticks from OWC that caused the exact same sort of instability that everyone else described. I had them replaced twice and had the same issue each time. Wish I had found this thread (and the apple support one) sooner, this has been going on for over a year.
OWC had to revise their external USB SSD container because the first revision didn’t have insulation and caused a risk of SSD shorting out. They aren’t always the best. There is a thread somewhere in this forum about it, and OWC acknowledging the issue and the fact a hardware revision was made.
Yeah not saying they're the best. Just that a lot of people go to OWC for RAM because they USED TO supply the correct stuff reliably, but now it doesn't matter.
So you haven't encountered any issues because of the non-standard timing? The timing on Apple's stock memory is 19-19-19, while the one you linked is 18-18-18. One of the purchasers at that link mentioned having issues running this in a 2020 iMac, and G.Skill suggested they should install the F4-2666C19D-64GRS (https://www.gskill.com/product/2/197/1610350870/F4-2666C19D-64GRS) instead of the F4-2666C18D-64GRS (https://www.gskill.com/product/2/197/1575884253/F4-2666C18D-64GRS) you're using.
G.SKILL Ripjaws Series 64GB DDR4 2666 Laptop Memory - Newegg.com
Buy G.SKILL Ripjaws Series 64GB (2 x 32GB) 260-Pin DDR4 SO-DIMM DDR4 2666 (PC4 21300) Laptop Memory Model F4-2666C18D-64GRS with fast shipping and top-rated customer service. Once you know, you Newegg!www.newegg.com
bought two of those
Also, are you getting the full 2666 MHz on these? Sometimes aftermarket memory runs at only 2400 MHz in the 2019/2020 iMacs.
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