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MP 7,1 Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

B

bxs

macrumors 65816
Original poster
Oct 20, 2007
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Seattle, WA
Subject: Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

I purchased 3rd party RAM for my MP7,1 in two separate purchases from the same vendor.

  1. First set purchased was for 8x 32GB R-DIMMs
  2. Second set purchased was for 4x 32GB R-DIMMs

In my attached image of the the received R-DIMMs it can be seen that the chip layout on the first set of 8x 32GB R-DIMMs is different from the second set of 4x 32GB R-DIMMs.

The attached image shows the front and back sides of each purchased sets. Top left image is one of the R-DIMMs in the first purchased set, and the bottom right image is one of the R-DIMMs in the second purchased set.

Should I be concerned ? Thanks :)
 

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bxs said:
Subject: Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

I purchased 3rd party RAM for my MP7,1 in two separate purchases from the same vendor.

  1. First set purchased was for 8x 32GB R-DIMMs
  2. Second set purchased was for 4x 32GB R-DIMMs

In my attached image of the the received R-DIMMs it can be seen that the chip layout on the first set of 8x 32GB R-DIMMs is different from the second set of 4x 32GB R-DIMMs.

The attached image shows the front and back sides of each purchased sets. Top left image is one of the R-DIMMs in the first purchased set, and the bottom right image is one of the R-DIMMs in the second purchased set.

Should I be concerned ? Thanks :)
Click to expand...

Did these modules from Nemix have the same exact model number ? They might be simply rebadging someone else's product . Also , the chip densities might be different between the two modules .
 
Last edited:
bxs said:
Subject: Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

I purchased 3rd party RAM for my MP7,1 in two separate purchases from the same vendor.

  1. First set purchased was for 8x 32GB R-DIMMs
  2. Second set purchased was for 4x 32GB R-DIMMs

In my attached image of the the received R-DIMMs it can be seen that the chip layout on the first set of 8x 32GB R-DIMMs is different from the second set of 4x 32GB R-DIMMs.

The attached image shows the front and back sides of each purchased sets. Top left image is one of the R-DIMMs in the first purchased set, and the bottom right image is one of the R-DIMMs in the second purchased set.

Should I be concerned ? Thanks :)
Click to expand...
Did your Mac Pro recognize them all?
 
OkiRun said:
Did your Mac Pro recognize them all?
Click to expand...
Both sets were purchased on Amazon at different times; the 8x 32GB set was purchased Dec 21, 2019 and the 4x 32GB set was purchased Jan 5, 2020.

The NVTEK invoice Item #s are identical for each purchase.
MR23400-324K04-G
B07X5D51NC

The Name on the invoices were identical
"NEMIX RAM 128GB 4x32GB DDR4-2933 PC4-23400 2Rx4 ECC Registered memory"

I have written to seller (thru Amazon's site) about the difference in chip layouts. So should hear back from them within a day.

I agree, the chip density is different comparing the two R-DIMMs in each purchased set.

I do not have my MP7,1 yet so cannot determine if I'm going to have a problem using all 12 R-DIMMs together.

Given that each set have different chip layouts and presumably different densities, will this affect memory performance and/or the way memory is allocated ?
 
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What is the significance of R-DIMMs having identical specification, same memory size (such as in the case 32GB) but having a different number of chips on the silicon?

  1. Is there a performance difference ?
  2. Is the number of memory ranks different?
  3. Will it cause some sort of imbalance when memory is being access and allocated ?
  4. What other issues might there be?

Thanks. :)
 
BTW... The first set of 8x 32GB R-DIMMs I purchased have twice as many chips as the second 4x 32GB R-DIMMs I purchase; 38 vs. 19.
 
bxs said:
Subject: Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

I purchased 3rd party RAM for my MP7,1 in two separate purchases from the same vendor.

  1. First set purchased was for 8x 32GB R-DIMMs
  2. Second set purchased was for 4x 32GB R-DIMMs

In my attached image of the the received R-DIMMs it can be seen that the chip layout on the first set of 8x 32GB R-DIMMs is different from the second set of 4x 32GB R-DIMMs.

The attached image shows the front and back sides of each purchased sets. Top left image is one of the R-DIMMs in the first purchased set, and the bottom right image is one of the R-DIMMs in the second purchased set.

Should I be concerned ? Thanks :)
Click to expand...
I chatted with an OWC technical support person today and put the question to the person. Basically asking what the difference is, if any, there maybe between a 32GB R-DIMM with 38 chips vs. another one with 19 chips, and was told there's no difference in the way the two R-DIMMs perform, and not to worry. :) 👍
 
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bxs said:
I chatted with an OWC technical support person today and put the question to the person. Basically asking what the difference is, if any, there maybe between a 32GB R-DIMM with 38 chips vs. another one with 19 chips, and was told there's no difference in the way the two R-DIMMs perform, and not to worry. :) 👍
Click to expand...
Thanks. I've been searching for the answer to this online with no luck. I've got 10 x4 and 2 x8 coming. I think, based on some private conversations, that I will keep the numbers paired ... all x4 paired and the two x8 paired.
 
Hello,

In this article, the author discovers the OWC memory config he used has 33% faster throughput than the factory Apple memory:

macperformanceguide.com

2019 Mac Pro: Memory Bandwidth

macperformanceguide.com

He wrote,

"Why is OWC memory substantially faster than Apple? One answer might be that the OWC 32GB modules have many more memory chips on each module, and that memory access could be interleaved (parallelized) within the chips on the module (???)."

That could help lead you in the right direction.
 
Theophilos said:
Hello,

In this article, the author discovers the OWC memory config he used has 33% faster throughput than the factory Apple memory:

macperformanceguide.com

2019 Mac Pro: Memory Bandwidth

macperformanceguide.com

He wrote,

"Why is OWC memory substantially faster than Apple? One answer might be that the OWC 32GB modules have many more memory chips on each module, and that memory access could be interleaved (parallelized) within the chips on the module (???)."

That could help lead you in the right direction.
Click to expand...

Yes, I came across that information the other day also.

At this time I'm in contact with NVTEK and they have agreed to replace all 12 of my 32GB R-DIMMs with a matching set of 12x 32GB R-DIMMs (each having 38 chips).
 
Last edited:
Last edited:
Theophilos said:
Hello,

In this article, the author discovers the OWC memory config he used has 33% faster throughput than the factory Apple memory:

macperformanceguide.com

2019 Mac Pro: Memory Bandwidth

macperformanceguide.com

He wrote,

"Why is OWC memory substantially faster than Apple? One answer might be that the OWC 32GB modules have many more memory chips on each module, and that memory access could be interleaved (parallelized) within the chips on the module (???)."

That could help lead you in the right direction.
Click to expand...


you do know that macperformanceguide.com is part of OWC, right?
 
bxs said:
Subject: Comparing a set of 8x 32GB R-DIMMs vs. a set of 4x 32GB R-DIMMs ?

I purchased 3rd party RAM for my MP7,1 in two separate purchases from the same vendor.

  1. First set purchased was for 8x 32GB R-DIMMs
  2. Second set purchased was for 4x 32GB R-DIMMs

In my attached image of the the received R-DIMMs it can be seen that the chip layout on the first set of 8x 32GB R-DIMMs is different from the second set of 4x 32GB R-DIMMs.

The attached image shows the front and back sides of each purchased sets. Top left image is one of the R-DIMMs in the first purchased set, and the bottom right image is one of the R-DIMMs in the second purchased set.

Should I be concerned ? Thanks :)
Click to expand...
Today I received 12x 32GB R-DIMMs from NVTEK all having the exact number of chips. Their replacement service was excellent, and no S&H was charged to me.
 
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