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Crazy idea. 32GB RAM modules in a cMP. Anyone tried this?
- Thread starter William Payne
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Hello
On my cMP 5.1 with 96GB of 1333 MHz DDR3 ECC (Monterey), I'm facing very long boot (Apple logo with crawling loading bar), even if everything works fairly well afterward.
I was never able to discover the root cause of the issue, I'm curious about this boot delays due to RAM you mentionned.
Could you provide me a link to the original information ?
Thanks a lot.
Hmmm, what did you do to your OpenCore config.plist that your DIMMs manufacturer, serial number and part number lists as "OpenCore"? Some special treatment for each and every slot? On my Mac (OC, 128 GB RAM) it looks different.
EDIT: ooh, OK, I see here https://forums.macrumors.com/thread...is.2046693/page-7?post=29717589#post-29717589
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The usual slow boot (I had a cMP genuine 5,1 with 128GB ram) seems to be when starting the machine and waiting for it to go through its checks. The Apple logo with the progress bar was usually fairly quick once it appeared. But waiting for the machine to chime was fairly sluggish after installing the ram.
Yes indeed, it's the POST RAM check, the more memory you have the slower it will be.
That machine had 128GB and also a lot of NVME storage, it was extremely slow to start up.
Once it was going no problem.
Yes... but I realized that I didn't need to build 12 DIMM Slots... I only needed to make sure the math was right for 8 slots.
Will somebody please help me out? I read somewhere that you cam max out the memory on a dual processor 5,1 2010 Mac Pro at 160G. I know that there are 32G modules available, so will the later OSs support these and allow you to mix different size modules? Any input will be appreciated. Thanks!!
You should read this thread from the 1st page and you will get answers to all your questions and possible future ones. This thread is not very long and full of useful information including how to setup the cMP with 32gb modules.
To summarise your question though, you cannot use 32gb module with standard macOS/OSX. But again, if you read here you will understand how we do so using Open Core.
I am currently running 6x32gb modules for a total of 192gb in my cMP 5,1.
PM me... I have 8 x 32GB DDR3 10600-R ECC that I purchased back in Nov 2022, that I offer for sale.
There is no practical difference between Samsung, Micron or Hynix DRAM. Quality of the integrator (who assembles the DIMMs) may differ, but even then, there are virtually no differences.
RAM in general is pretty solid anyway, perhaps the most reliable component in a modern PC.
Thanks for the offer, but now i allready ordered some from Germany where i live.
But, as i think it's the same Hynix like you use, is there any chance, you (or did you allready?) post your config.plist? I'd very much rather do the necessary adjustments manually than playing around with Clover in a cMP.
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I needed an ESXI box and my ThinkStation died. Luckily it used the same ram as my 5,1.
ESXI 6.7u3b sees all 128GB of RAM. I have 4 32gb sticks on my single-processor 5,1. It took some fiddling to get the Mac to see the RAM; for some reason one stick didn't work in slot 1 but works fine in slot 2.
To get this to work I first booted up with the option key amd 16gb of RAM installed. I installed ESXI on one of my internal SSDs, then shut down and replaced the sticks with the 32GB sticks.
FYI to anyone out there who needs this. I'll be installing a FreeNAS VM and a bunch of MacOS VMs now, which'll replace a Mac mini and an old Retina 15". It'll be nice putting this old girl back to work!
ESXI 6.7u3b sees all 128GB of RAM. I have 4 32gb sticks on my single-processor 5,1. It took some fiddling to get the Mac to see the RAM; for some reason one stick didn't work in slot 1 but works fine in slot 2.
To get this to work I first booted up with the option key amd 16gb of RAM installed. I installed ESXI on one of my internal SSDs, then shut down and replaced the sticks with the 32GB sticks.
FYI to anyone out there who needs this. I'll be installing a FreeNAS VM and a bunch of MacOS VMs now, which'll replace a Mac mini and an old Retina 15". It'll be nice putting this old girl back to work!
Would 64GB modules work, say Samsung m386b8g70de0. 3 of these and 3x32GB would give the full possible 288GB, in triple channel mode with 2 slots free. Anyone tried these?
So far these are not functioning and will not get past post. Ram LED lights up on the board. I have tried multiple sticks, to no avail. My quad rank 32 GB sticks work fine. My config in open core is set up for 32gb. If I add one of the quad and one of the dual ranked dims it will boot but only read the quad. And since they're not getting past post I can't see them in Windows either. It is already known that the 5.1 will not take LR dimms and these are somewhat similar as they use rank multiplication and a onboard controller, but I don't think they are going to workeven though they are 10600r and not 10600L.
It's a shame as i did a lot of research but couldn't find anyone running them on these particular systems. The netlist hypercloud ram is known to work with Xeon 5600 series CPUs though and is supposed to be interchangeable with rdimms with no changes needed to the BIOS. But again that is for Windows and we all know that Mac is different. I will attempt to do some further testing when I get home
HCDIMMs are not supported by MacPros. It's not a JEDEC standardized DIMM and, AFAIK, only some IBM/HP servers and some very specialized server motherboards had support for this type of DIMMs.
Wouldn't have been worth all the hassle after all.
As extensive testing with 16GB modules showed, 1333 vs. 1066 is plain cosmetic if anything at all. More often than not 1066 have even been faster due to the shorter latency of 7 vs. 9. But it's absolutely marginal in benchmarks and will likely be even less in "real life".
Just tested all my ram configurations with dual-rank 16gb dimms and quad-rank 32gb dimms. Couldn't test 8x16gb as I only have 6 of them. The mhz is not correct in about mac for the 32gb setup with 6 and 8 as its just spoofed by opencore. I am suprised at the results though and thought that the 6x16gb @1300mhz would have been faster than the 6x32gb @ 1066mhz, but you thoughts on latency seem to be correct. Thanks for the input. Seems I will be sticking with the 6x32gb set up.
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Yes! You can enter whatever you like at the memory key in the config.plist So i have seen some nice speeds! 😝
I'm afraid it's only half the truth. Large sequential writes/reads should be faster for the faster frequency. But, as random access to small chunks of data is likely the more common situation, overall the quad-rank-dimms might be the faster by a very small margin. Not noticeable anyway.
Hello All,
I am new here, I have 2019 MAC PRO4.1>5.1, I did upgrade firmware, now, I need help, I only have Single CPU, I did change to 32GB x4=128GB, I did made change to my config file at open core, when I boot up, I did hear the sound, it looks good, I can see the open core pick up menu, but it hangs at Apple logo, not sure where go wrong, here is my config, can anyone help? Thanks
I am new here, I have 2019 MAC PRO4.1>5.1, I did upgrade firmware, now, I need help, I only have Single CPU, I did change to 32GB x4=128GB, I did made change to my config file at open core, when I boot up, I did hear the sound, it looks good, I can see the open core pick up menu, but it hangs at Apple logo, not sure where go wrong, here is my config, can anyone help? Thanks
new update!
I did try using Ubuntu USB to boot up my mac pro, i can see the 125GB memory, so I am sure, that the mac pro with 1 single CPU can boot without any issue, now, I still do not know why when I boot up to OSX, only show the apple logo and hang in there, anyone can help? Thank you!
I did try using Ubuntu USB to boot up my mac pro, i can see the 125GB memory, so I am sure, that the mac pro with 1 single CPU can boot without any issue, now, I still do not know why when I boot up to OSX, only show the apple logo and hang in there, anyone can help? Thank you!