Is it possible you have this backwards? I believe I read for the same amount of ram 2Rx4 was faster than 2Rx8, but this is far from my wheelhouse.
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MP 7,1 3rd party RAM vendors for Mac Pro 7,1
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Is it possible you have this backwards? I believe I read for the same amount of ram 2Rx4 was faster than 2Rx8, but this is far from my wheelhouse.
@theatwar @bxs @aliengirl @repoman27 @barnyard @profdraper @the_zee @MarciaFunebre anyone have 2 sticks of the OEM 8GB 2933MHz RAM they want to sell? I’d be most appreciative. Send a DM 
Hey folks,
reading this with interest.... damn, never knew ram could be so confusing!
Not sure of the difference between LR/R dims but for the sake of making it straightforward Can I assume that the LR Dimms are faster? Currently Spec'ing a BTO on a budget..... like that's even possible... but rather get a lower amount of fastest possible now and add t it later...
Also, can I keep the base 32GB it ships with?
Cheers
reading this with interest.... damn, never knew ram could be so confusing!
Not sure of the difference between LR/R dims but for the sake of making it straightforward Can I assume that the LR Dimms are faster? Currently Spec'ing a BTO on a budget..... like that's even possible... but rather get a lower amount of fastest possible now and add t it later...
Also, can I keep the base 32GB it ships with?
Cheers
Gr1f,
I think all the 7,1 memory runs at the same speed unless you have the base CPU; it runs the memory a bit slower, but any higher core count CPU will run the same RAM at the maximum speed.
If you visit this link https://www.apple.com/mac-pro/specs/ you'll see the 8-core runs the RAM at 2666MHz. Any higher core CPU runs it at 2933MHz. The 32GB that comes with the base 8-core CPU is capable of the 2933MHz and can be reused.
As to the RDIMM/LRDIMM, the main difference is that after about 32GB per module (or more, not sure where the break is?), LRDIMMs are required. For lower capacity chips such as 8GB or 16GB, RDIMMs are fine. Not sure bout the max size for the RDIMMs but I hope you get the idea. The base 8GB sticks are RDIMMs.
In either case, all RAM needs to be either RDIMM or LRDIMM; the two types are incompatible and should not be mixed.
So if you are shooting for a terabyte or so total RAM you'll need to get LRDIMMs.
As far as I know, speeds are all the same: 2933MHz
BTW, I reused the 4x8GB=32GB sticks that came with mine; added 8 more to make 96GB. When I had an 8 core CPU the RAM ran at 2666MHz; when I upgraded the CPU all the RAM now runs at 2933MHz.
Hope this helps,
Tom
I think all the 7,1 memory runs at the same speed unless you have the base CPU; it runs the memory a bit slower, but any higher core count CPU will run the same RAM at the maximum speed.
If you visit this link https://www.apple.com/mac-pro/specs/ you'll see the 8-core runs the RAM at 2666MHz. Any higher core CPU runs it at 2933MHz. The 32GB that comes with the base 8-core CPU is capable of the 2933MHz and can be reused.
As to the RDIMM/LRDIMM, the main difference is that after about 32GB per module (or more, not sure where the break is?), LRDIMMs are required. For lower capacity chips such as 8GB or 16GB, RDIMMs are fine. Not sure bout the max size for the RDIMMs but I hope you get the idea. The base 8GB sticks are RDIMMs.
In either case, all RAM needs to be either RDIMM or LRDIMM; the two types are incompatible and should not be mixed.
So if you are shooting for a terabyte or so total RAM you'll need to get LRDIMMs.
As far as I know, speeds are all the same: 2933MHz
BTW, I reused the 4x8GB=32GB sticks that came with mine; added 8 more to make 96GB. When I had an 8 core CPU the RAM ran at 2666MHz; when I upgraded the CPU all the RAM now runs at 2933MHz.
Hope this helps,
Tom
It depends on the size of the RAM chips. When the number of chips hits a certain level - you need LRDIMMs to reduce the electrical load ("LR" means "Load Reduced").
I have systems with 32 GiB LRDIMMs and systems with 64 GiB RDIMMs.
Thanks for the response... yea been reading up on it.
Think I'm gonna get the 16core as the lower end CPUs make no sense to me in terms of price/performance.
So I'm be happy with 160GB. I could keep the 4 8GB RDIMMs and add in 2X64 GB RDIMMs I guess. Nemix seems reasonable enough.
LRDIMMs are additionally buffered, so they require more power in comparison to RDIMMs, and have increased latency. Speed and latency are different things—think of two people who run at the same speed, but one is a little slower to start. It's not a big deal, but basically use LRDIMM when you need the additional capacity it affords (can't mix 'em). Otherwise, RDIMM.
You want memory in groups of six, of the same size. In a nut shell, memory must be in pairs and six gives about 3/3 memory bandwidth (100%), four gives 2/3, two gives 1/3. Obviously, the last one is the most important to avoid. When you have four 8 GB and two 64 GB, you'll have 48 GB running at 100% bandwidth, and 112 GB—most of your memory space—at 33% bandwidth. Best to sell the 8 MB sticks, I went that route, a lot of people want them to fill out their memory space to either 6 or 12 sticks.
OK so.... 192GB via 6 32GB RDIMMs then
I maxed my mac pro out with nemix ram. I did have an issue, but it wasn't the fault of the RAM. It turned out to be a ram retention slot was faulty. But at the time I thought it was my ram and nemix were extremely helpful, and happy to exchange my ram and in fact they did. In the end apple fixed my problem which involved replacing a big part of my computer including the motherboard and my internal drive. My nemix ram has been working since then without any problems. All happy little green dots everytime i check it.
ry,
Have a look here: https://support.apple.com/en-ca/HT210405
Since you're going above 384GB, you probably should use LRDIMMs. Apple supplies the LRDIMMs with any amount of RAM from 384GB.
And also "Do not mix R-DIMMs and LR-DIMMs."
Tom
Have a look here: https://support.apple.com/en-ca/HT210405
Since you're going above 384GB, you probably should use LRDIMMs. Apple supplies the LRDIMMs with any amount of RAM from 384GB.
And also "Do not mix R-DIMMs and LR-DIMMs."
Tom
Hi all.
I'm planning to add 2x64 RDIMM for my Mac Pro 7.1 (3.2 GHz 16コアIntel Xeon W). Now it has 6x16GB RDIMM.
The candidate RAM list is here.
memory.net
I’m thinking about getting Samsung's M393A8G40AB2-CVF or M393A8G40MB2-CVF but I have two questions.
1: What's the difference between these two memories, A-die and M-die?
2: Any problem with mixing 2x64GB and 6x16GB?
Thank you,
Yutani
I'm planning to add 2x64 RDIMM for my Mac Pro 7.1 (3.2 GHz 16コアIntel Xeon W). Now it has 6x16GB RDIMM.
The candidate RAM list is here.
Pro 2019 Archives
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memory.net
I’m thinking about getting Samsung's M393A8G40AB2-CVF or M393A8G40MB2-CVF but I have two questions.
1: What's the difference between these two memories, A-die and M-die?
2: Any problem with mixing 2x64GB and 6x16GB?
Thank you,
Yutani