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mrt209

macrumors 6502
Original poster
Nov 21, 2010
445
44
USA/Germany
I am looking to upgrade the memory in my Mid 2010 5,1 6-core Mac Pro and I want to get to at least 48gb. If I understand correctly it is best to use 3 sticks (like I am currently doing... 3x4gb) due to the triple channel memory controller. Is there really a noticeable difference in running 3x16gb vs 4x16gb? If I buy the 4x16gb from the eBay link below is best to leave one stick uninstalled?


Can someone help me verify if these would work and any advice on where to buy or what a good deal is? I am very much a noob...


https://www.datamemorysystems.com/dm61-765/ x3




My Mac:

Mac Pro (Mid 2010)
3.33 GHz 6-Core Intel Xeon
12 GB 1333 MHz DDR3
Radeon RX 580 8 GB
Mojave


Thanks!
 

mikas

macrumors 6502a
Sep 14, 2017
900
650
Finland
About memory channels: There is a difference in speed with benchmarks, but in real world usage you hardly notice anything - unless your workflow is spesifically demanding with ram. If you can manage with 48GB, I'd buy 3x 16GB 1333MHz modules. If your workflow consumes more than 48GB, then of course 64GB is a better advice. OWC modules seem a little bit pricey in my opinion.

Attached my RAM tests from couple of years ago. The only difference here is amount of installed RAM, 3 modules versus 4 modules.

1575907340141-png.881656
 
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mrt209

macrumors 6502
Original poster
Nov 21, 2010
445
44
USA/Germany
About memory channels: There is a difference in speed with benchmarks, but in real world usage you hardly notice anything - unless your workflow is spesifically demanding with ram. If you can manage with 48GB, I'd buy 3x 16GB 1333MHz modules. If your workflow consumes more than 48GB, then of course 64GB is a better advice. OWC modules seem a little bit pricey in my opinion.

Attached my RAM tests from couple of years ago. The only difference here is amount of installed RAM, 3 modules versus 4 modules.

1575907340141-png.881656

Thanks a lot for the reply and the benchmarks. I don't think I need more than 48GB so will just go with 3x16gb. Agree with the OWC, going to go with one of the other two... Going to try and see if the eBay seller will sell me 3x16gb for a good price, if not I'll just buy from data memory systems since I have seen a few people here recommend them in other posts.
 

MacUser2525

Suspended
Mar 17, 2007
2,097
377
Canada
Thanks a lot for the reply and the benchmarks. I don't think I need more than 48GB so will just go with 3x16gb. Agree with the OWC, going to go with one of the other two... Going to try and see if the eBay seller will sell me 3x16gb for a good price, if not I'll just buy from data memory systems since I have seen a few people here recommend them in other posts.

Make sure you get the 1333 mhz ram dual rank ram. The link you had to the pc8500 is not it. The quad rank ram even if the 1333mhz will not run at that speed in your machine due to the firmware limitation. I think it is the 2R in the name you need to look for and pc10600 is the term for the 1333mhz ram.
 
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Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
Make sure you get the 1333 mhz ram dual rank ram. The link you had to the pc8500 is not it. The quad rank ram even if the 1333mhz will not run at that speed in your machine due to the firmware limitation. I think it is the 2R in the name you need to look for and pc10600 is the term for the 1333mhz ram.

It is well known with UP Nehalem cMPs that three identical memory modules will provide the highest possible bandwidth . Go with used 1333 MHz ECC enterprise modules from eBay . They are made by Samsung , Hynix , Micron , Nanya , Elpida . Three 16GB modules should run a total of $60 - 75 . Verify the whole shebang with Memtest for Mac .

Here's a link to known good modules :

 
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mrt209

macrumors 6502
Original poster
Nov 21, 2010
445
44
USA/Germany
Make sure you get the 1333 mhz ram dual rank ram. The link you had to the pc8500 is not it. The quad rank ram even if the 1333mhz will not run at that speed in your machine due to the firmware limitation. I think it is the 2R in the name you need to look for and pc10600 is the term for the 1333mhz ram.

Thank you! Totally missed that listing wasn't 1333 MHz.


It is well known with UP Nehalem cMPs that three identical memory modules will provide the highest possible bandwidth . Go with used 1333 MHz ECC enterprise modules from eBay . They are made by Samsung , Hynix , Micron , Nanya , Elpida . Three 16GB modules should run a total of $60 - 75 . Verify the whole shebang with Memtest for Mac .

Here's a link to known good modules :


Thanks a lot! Found the same memory new for $26 each. Going to verify first, if not I'll just buy from the listing you posted.
 

MacUser2525

Suspended
Mar 17, 2007
2,097
377
Canada
It is well known with UP Nehalem cMPs that three identical memory modules will provide the highest possible bandwidth . Go with used 1333 MHz ECC enterprise modules from eBay . They are made by Samsung , Hynix , Micron , Nanya , Elpida . Three 16GB modules should run a total of $60 - 75 . Verify the whole shebang with Memtest for Mac .

Here's a link to known good modules :



It is well known according to tsialex that quad ranked modules do not give the top speed. I will go with what he said in that thread I first saw this in as to why the OP could not get the rated 1333mhz speed. That man knows more than most apple engineers I think or at least as much. With all the guides he has posted on the inner workings of these machines and his abilities to redo the chips on the logic board. You are welcome to your opinion I will trust his over yours.
[automerge]1577714464[/automerge]
Thank you! Totally missed that listing wasn't 1333 MHz.


You are welcome.
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
Snow Tiger said:
"It is well known with UP Nehalem cMPs that three identical memory modules will provide the highest possible bandwidth . Go with used 1333 MHz ECC enterprise modules from eBay . They are made by Samsung , Hynix , Micron , Nanya , Elpida . Three 16GB modules should run a total of $60 - 75 . Verify the whole shebang with Memtest for Mac .

Here's a link to known good modules :

www.ebay.com

16GB 2RX4 PC3L-10600R M393B2G70BH0-YH9 ECC DDR3 MEMORY SAMSUNG 404776236920 | eBay
16GB DDR3 SDRAM. 1 X 16Gb, 1333MHZ DDR3-1333/PC3L-10600. SAMSUNG PART NUMBER - M393B2G70BH0-YH9.
www.ebay.com
Click to expand...

"It is well known according to tsialex that quad ranked modules do not give the top speed. I will go with what he said in that thread I first saw this in as to why the OP could not get the rated 1333mhz speed. That man knows more than most apple engineers I think or at least as much. With all the guides he has posted on the inner workings of these machines and his abilities to redo the chips on the logic board. You are welcome to your opinion I will trust his over yours."

If you were to closely examine the module model I recommended to the OP , they are dual rank . The UP cMP 5,1 only has a single bank of four memory slots . The bank will accept a total of 8 rank positions for all the installed modules .

It is possible with this platform to install three matching dual rank memory modules , as they would consume only six rank positions .

It is not possible with this platform to install three matching quad rank memory modules , as they would need to consume twelve rank positions .

That is the reason quad rank memory in a cMP can never activate the Nehalem processor's tri channel memory bandwidth optimization . It's not that quad rank modules are somehow inferior . It's just that not enough of them can be installed to obtain the best bandwidth here .

I'm not certain if tsialex is a trained engineer or a self taught one . And he is a smart cookie that I trust as well . I am a System Builder with fifteen year's experience building workstations that are deployed in production environments .
 

MacUser2525

Suspended
Mar 17, 2007
2,097
377
Canada
I'm not certain if tsialex is a trained engineer or a self taught one . And he is a smart cookie that I trust as well . I am a System Builder with fifteen year's experience building workstations that are deployed in production environments .

Who knows where the knowledge comes from never seen that posted by him. First one I built had to be 30 years ago, my 80286, no clue how many thousands I have built since then...
 

MacUser2525

Suspended
Mar 17, 2007
2,097
377
Canada
He is a very humble man ...

And very helpful always answering the countless post I have seen him do. Always at it with spreading the knowledge to others in need of it. He gave up doing it, but for a while there he was editing firmware every day for people.
 
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