MP 1,1-5,1 cMP & nMP {MacPro 4,1 & 5,1} Memory Upgrade Compatibility and FAQ

n8ballz

macrumors newbie
Original poster
Jan 4, 2018
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Here is the start to a mega thread of memory upgrades and FAQ

Please feel free to post your working configurations along with your brand and model numbers.


A single W36xx CPU can support up to 56GB memory (3x16 + 8)
A single X56xx CPU can support up to 64GB memory (4x16)
A dual X56xx CPU can support up to 160GB memory (5x32)

**Currently there is NO confirmation if 32GB DIMMs can be used on a single processor cMP to further push up the memory size limit.**


Apple's Recommendation:
  • PC3-10600E, 1333 MHz, DDR3 SDRAM UDIMMs
  • Error-correcting code (ECC)
  • 72-bit wide, 240-pin ECC modules
  • 36 ICs maximum per ECC UDIMM

The Mac Pro can accept slower memory. It just run slower.

The Mac Pro can accept faster memory, the DIMM will be automatically downclock to match the CPU / logicboard's max possible speed.

There is NO requirement to use ECC RAM on the cMP.

Memory specifications differ between 4,1 and 5,1

DIMM Supported Model Numbers (cMP 5,1)
- Users have reported that normal non-ECC DIMMs will work
<links and additional info needed>

UDIMM Supported Model Numbers (cMP 5,1)
- Apple's recommended RAM spec
Where to buy:
MacSales
eBay
Newegg
Amazon

Brands and Model Numbers:
Crucial
CT8G3W186DM
CT16G3W186DM

Kingston

Samsung
M391B5273CH0-CH9

Hynix

ELPIDA
RDIMM Supported Model Numbers (cMP 5,1)
- Yes RDIMMs work but you cannot mix with UDIMMs
- Perfomance differential is nominal

Where to buy:
eBay
Amazon
Newegg

Brands and Model Numbers:
Hynix
-- 8GB --
HMT31GR7BFR4C-H9 D7 AB

Samsung
-- 8GB --
M393B1K70CH0-CH9

Micron
-- 8GB --
MT36JSZF1G72PZ-1G4D1DD
-- 16GB --
MT36KSF2G72PZ-1G4

ELPIDA
-- 8GB --
EBJ81RF4ECFA-DJ-F​
 
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flowrider

macrumors 603
Nov 23, 2012
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AFAIK, RAM specifications are the same between a 4,1 and a 5,1 cMP. Especially when the 4,1 is upgraded to 5,1 firmware so the 4,1 can use faster and more cores CPUs.

As for memory suppliers, I avoid eBay and MacSales (OWC) at all costs. Many eBay sellers sell counterfeit equipment and OWCs memory has proven to be suspect.

My RAM supplier since 1986, has been:

https://www.datamemorysystems.com/apple-memory/

They guarantee for Life. They are Mac specialists. In all the years I have been dealing with them, I have never received a bad piece of equipment. I recommend them highly.

Lou
 

h9826790

macrumors G5
Apr 3, 2014
13,484
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Hong Kong
Just post a link here to let the others know that (you may update the OP to prove that non ECC RAM can work)

1) different size DIMM can be mixed together.
2) ECC RAM and be mixed with non ECC RAM (but ECC will be disabled)
3) faster DIMM can be mixed with slower DIMM (all DIMM will run follow the slower DIMM's speed)
4) DIMM in non-optimum slots can boot, but the OS will pop up a windows to ask the user to install the RAM as per Apple's suggestion

https://forums.macrumors.com/threads/can-i-mix-memory-size.1903411/#post-21638766

Also, BOTH 1.5V and 1.35V DIMM can work on cMP. 1.35V DIMM actually support both 1.35V and 1.5V, and will run at 1.5V on cMP.

And it's highly prefer to buy 2Rx4 DIMM (memory rank), other rank (e.g. 4Rx4) may work, but may also cause issue (e.g. no boot if all slots used. Or negotiate at slower clock speed)
[doublepost=1515090157][/doublepost]
AFAIK, RAM specifications are the same between a 4,1 and a 5,1 cMP. Especially when the 4,1 is upgraded to 5,1 firmware so the 4,1 can use faster and more cores CPUs.

As for memory suppliers, I avoid eBay and MacSales (OWC) at all costs. Many eBay sellers sell counterfeit equipment and OWCs memory has proven to be suspect.

My RAM supplier since 1986, has been:

https://www.datamemorysystems.com/apple-memory/

They guarantee for Life. They are Mac specialists. In all the years I have been dealing with them, I have never received a bad piece of equipment. I recommend them highly.

Lou
Technically, they are different. 4,1 use 1066MHz RAM, and 5,1 use 1333MHz RAM. In fact, from the Apple's official manual.

4,1 requirement

  • PC3-8500,1066 MHz, DDR3 SDRAM UDIMMs
  • 72-bit wide, 240-pin modules
  • 18 memory ICs maximum per UDIMM
  • Error-correcting code (ECC)

5,1 requirement

  • PC3-10600E,1333 MHz, DDR3 SDRAM UDIMMs
  • Error-correcting code (ECC)
  • 72-bit wide, 240-pin ECC modules
  • 36 memory ICs maximum per ECC UDIMM

    However, in real world, all these memory can be used on both cMP. For 4,1 both DIMM will run at 1066MHz, but on a 5,1 the 1333MHz can run at 1333 (with the correct CPU).
 

flowrider

macrumors 603
Nov 23, 2012
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[doublepost=1515129818][/doublepost]
Technically, they are different. 4,1 use 1066MHz RAM, and 5,1 use 1333MHz RAM. In fact, from the Apple's official manual.

Again, they are the same - Did you not read my post


Especially when the 4,1 is upgraded to 5,1 firmware so the 4,1 can use faster RAM and more cores CPUs.

Apple wrote the spec because the stock cMP 4,1 CPUs only supported 1066MHz.


However, in real world, all these memory can be used on both cMP. For 4,1 both DIMM will run at 1066MHz, but on a 5,1 the 1333MHz can run at 1333 (with the correct CPU).
cMP 4,1 with upgraded CPUs and firmware will run @ 1333MHz.


Lou
 
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h9826790

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[doublepost=1515129818][/doublepost]


Again, they are the same - Did you not read my post





Apple wrote the spec because the stock cMP 4,1 CPUs only supported 1066MHz.




cMP 4,1 with upgraded CPUs and firmware will run @ 1333MHz.


Lou
Obviously they are not the same, did you read my posts? I list out the spec from which quote from the official Apple Technician Guide. Are those number looks identically? They can be mixed used doesn’t mean they are the same. Is that hard to understand?

This post is not just for 5,1. But also applicable for 4,1 (which didn’t flashed to 5,1). We should make it more clear for all reader, but not just say “they are the same” when clearly 4,1 cannot “support” 1333 (but only can “work” with 1333 DIMM).
 

nigelbb

macrumors 65816
Dec 22, 2012
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This post is not just for 5,1. But also applicable for 4,1 (which didn’t flashed to 5,1).
Please could you change the thread title to reflect the fact that only this is only about RAM for the 4,1 & 5,1 & ignores thé 1,1 2,1 & 3,1. Better still don’t change the thread title but include the information for all cMPs. It’s pretty straightforward as the 1,1 2,1 & 3,1 can all use the same 667MHz or 800MHz FB-DIMMs
 

h9826790

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Apr 3, 2014
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Please could you change the thread title to reflect the fact that only this is only about RAM for the 4,1 & 5,1 & ignores thé 1,1 2,1 & 3,1. Better still don’t change the thread title but include the information for all cMPs. It’s pretty straightforward as the 1,1 2,1 & 3,1 can all use the same 667MHz or 800MHz FB-DIMMs
This is not my thread, I also suggested the OP to do that.
 

flowrider

macrumors 603
Nov 23, 2012
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^^^^Upgraded CPUs like the X5677, X5680, X5690 and etc will run with DDR3-800 ,DDR3-1066, DDR3-1333 clocked RAM.

Lou
 

ActionableMango

macrumors G3
Sep 21, 2010
9,511
6,701
Will a cMP with upgraded processor run with non-Apple lower clock speed RAM or not at all?
There seems to be a lot of confusion about this. I will try to be clear and thorough so we can put it to rest.
  • Several CPU configurations that Apple shipped in the 4,1 and 5,1 are 1333 capable, so you don't necessarily need an "upgraded" CPU. The CPU upgrade guide identifies which CPUs support which bus speed.

  • 1066 and 1333 components are all operationally compatible with each other, but will operate at the slowest component's speed.

  • There are three components involved. If any one of them are limited to 1066, then all will run at 1066. If all three are 1333, then they will run at 1333. To run at 1333, the three components are:
  • The installed CPU(s) must be 1333-capable Nehalem or Westmere
  • All of the installed RAM sticks must be 1333-capable
  • Any version 5,1 firmware (these can also be installed on a 4,1)
    Or a 4,1 with firmware version MP41.0081.B08
 
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adam9c1

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May 2, 2012
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ActionableMango,

So if I have a 2009 4,1 flashed to 5,1 and two X5690 installed will this machine post/power up/run with non-Apple RAM rated at 1066?
 

adam9c1

macrumors 68000
May 2, 2012
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for me the key was non-Apple RAM

I replaced CPU in another cMP and went with 1066 based bus speed chip because I was not sure if this combo would work. Now I know.
;-)
 

Silencio

macrumors 68020
Jul 18, 2002
2,394
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Is it possible to run 64GB (4x16GB) in a single processor cMP? I've tried numerous sets of four matching 1333 DIMMs in some of my Mac Pros (both 4,1's flashed to 5,1 and native 5,1s, running either X5680 or X5690 processors), and can't get the systems to boot in that configuration.

I might need to investigate whether my memory is 4Rx4 as mentioned above.
 

flowrider

macrumors 603
Nov 23, 2012
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for me the key was non-Apple RAM
Apple Ram, Shmapple RAM, doesn't matter. It's the RAM specs that matter. Apple doesn't make and has never made RAM, they buy it just like you or me, but for a much lower price of course!

Lou
[doublepost=1515193928][/doublepost]
Is it possible to run 64GB (4x16GB) in a single processor cMP? I've tried numerous sets of four matching 1333 DIMMs in some of my Mac Pros (both 4,1's flashed to 5,1 and native 5,1s, running either X5680 or X5690 processors), and can't get the systems to boot in that configuration.

I might need to investigate whether my memory is 4Rx4 as mentioned above.
I've read of problems with that configuration. The problem is associated with the CPUs in the cMP 4,1 and 5,1 having three memory channels. In Apples configuration the third and fourth channel are physically tied together. Have you tried filling only three slots (slots 1 thru 3) and leaving slot 4 MT? If not, give it a try. If that works and 48GBs is not enough for you, I've heard that putting a smaller DIMM (8GB) in slot 4 may work.

Lou
 
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h9826790

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I've read of problems with that configuration. The problem is associated with the CPUs in the cMP 4,1 and 5,1 having three memory channels. In Apples configuration the third and fourth channel are physically tied together. Have you tried filling only three slots (slots 1 thru 3) and leaving slot 4 MT? If not, give it a try. If that works and 48GBs is not enough for you, I've heard that putting a smaller DIMM (8GB) in slot 4 may work.

Lou
AFAIK, the triple channel architecture never stop the 4th slot being functioning properly. I bet it has nothing to do with the triple channel, but more on the DIMM spec.

Since he's just talking about 64GB of RAM, I don't think OS version make the difference (the older OS support less RAM).

And he also stated that he use X5680 / X5690 but not the W36xx CPU. Therefore, sure it can support 64GB (4x16GB). It's a known fact.

So, the biggest suspect here is actually the DIMM spec. The most common problem I've seen so far is the "wrong" memory rank.
 
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Silencio

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Jul 18, 2002
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Okay, I opened another can of worms in the Mac Pro forum. For someone who's more of a lurker than a poster these days, I'm getting distressingly good at it. You guys are both members whose opinions and knowledge I respect.

I've only ever had problems with 4x16GB DIMMs in single processor Mac Pros. 4x8GB or 4x4GB, never a problem. And I got 8x16GB DIMMs to work just fine in one of my dual processor Mac Pro 5,1s (dual X5690). I am reluctant to buy more 16GB PC1333 ECC DIMMs for these aging machines, but bumping up the RAM from 48GB to 64GB would realistically help me get a little more mileage out of them.

All my 16GB DIMMs are from OWC and TransIntl, and I'm almost 100% certain they're all dual rank.
 
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