MP 1,1-5,1 cMP 5,1 RAM compatibility

[niallcook]

Quick intro: long time Mac user. Been running a cMP 5,1 (mid 2010) for some years, mainly doing graphics (Adobe CC), office and web app development. Recently decided to extend the life of the cMP with a few upgrades. So far I've installed a Sapphire RX580 and EVO 970 SSD on PCIe, upgraded to 144 F/W and Big Sur. Just ordered a pair of X5677s (for £30!) to replace the original E5620s (dual processor, obviously) as I decided I didn't really need the extra cores (or cost) of the X5690.

Now I'm looking at RAM. When I got it, it had 4 x 4Gb Corsair XMS3 sticks. I added 2 x 8Gb sticks to match. So currently running 32Gb. Debating whether it's worth going to 64Gb or further. Options are to dump the 4Gb and get 6 x 8Gb XMS3 sticks. Or I currently have the option of buying 8 x 8Gb Samsung M393B1K70CHD-CH9 sticks to replace the existing RAM for £70 (with 3 month warranty).

Will this Samsung RAM work in this machine? I couldn't see it in the compatibility list, but I've also seen threads from people asking the same question (but no follow-up to know whether it worked or not).

Thanks in advance. And great forum – was really helpful in my decision to go for the X5677 processors.

 

[TECK]

Any PC3L-10600R DDR3-1333MHz 2Rx4 server memory will work, search eBay to get great prices. This is what I use in my Mac (6 sticks):

BTW, your Mac will operate slightly faster if you use 6 sticks, instead of 8.

 

[niallcook]

Brilliant thanks

 

[tsialex]

Any PC3L-10600R DDR3-1333MHz server memory will work, search eBay to get great prices. This is what I use in my Mac (6 sticks):

View attachment 1680520

View attachment 1680529

BTW, your Mac will operate slightly faster if you use 6 sticks, instead of 8.

Sorry, but you are mistaken, no Quad Rank (4Rxyy) memory works at 1333MHz, when it works, works at 800MHz.

Memory for Mac Pros early-2009 to mid-2012 needs to be Dual Rank, the 2Rx4 on your photo:

There are other limitations like the number of RAM chips on the board and other more complicated things, that's why we usually only recommend part numbers that are tested and known to work fine.

 

[TECK]

Yes, I updated the reply after I realized I missed the 2Rx4 part.

 

[IowaLynn]

I find it has to start research at OWC MacSales

Memory Upgrades for 2010-2012 Apple Mac Pro from OWC

Easily upgrade the memory of your 2010-2012 Apple Mac Pro up to 128GB. We also provide refurbished Macs, SSDs, external storage, docks, and more!

eshop.macsales.com

Install videos and support plus they will buy back your Apple memory. Also use Crucial memory finder for supported configurations.

 

[TECK]

I find the OWC memory quite expensive. For example, I purchased the Hynix 128GB (8x16GB) for $160USD, from an eBay seller. Hynix and Samsung are the best brands used into production servers.

 

[niallcook]

I can get 8x8GB Samsung memory for £70 with a 3 month warranty. The equivalent from OWC would be three times as much. Whilst of course the OWC memory is new, that's quite a significant multiple. My question was really whether the Samsung memory would work.

However, TECK seems to be suggesting that 4X16GB or even 6x16GB might be a better choice.

 

[flyproductions]

Sorry, but you are mistaken, no Quad Rank (4Rxyy) memory works at 1333MHz, when it works, works at 800MHz.

I had this here working nicely at 1066MHz.

They only dropped to 800 when all 4 slots of one CPU had been used.

And due to the lower latency (7 istead of 9) at 1066 they even produced slightly better results with Geekbench's memory test, compared to 2R-modules. Logically there could be better performance expected for big transfers with 2R/1333MHz and for random access with 4R/1066MHz. But none of this should be actually noticeable in real world scenarios.

 

[tsialex]

I had this here working nicely at 1066MHz.

View attachment 1680958

They only dropped to 800 when all 4 slots of one CPU had been used.

And due to the lower latency (7 istead of 9) at 1066 they even produced slightly better results with Geekbench's memory test, compared to 2R-modules. Logically there could be better performance expected for big transfers with 2R/1333MHz and for random access with 4R/1066MHz. But none of this should be actually noticeable in real world scenarios.

You got lucky there, some quad rank RAM works at 1066MHz, if you don't use the fourth slot. The real problem is that a lot, if not most, quad rank DIMMs don't even get recognised because of the quantity of memory chips on board.

I've been burned so much times with sellers sending quad rank DIMMs that I read all the pertinent documentation for the Tylersburg platform to understand the intricacies of the memory controller, it's so much complicated to get a working config with quad rank that it's not worth to try.

 

[TECK]

@niallcook If you can find a good deal and plan to continue using your Mac for a while like I do, buy 6x16GB PC3L-10600R DDR3-1333MHz 2Rx4. I’m using OpenCore to make my Mac supported. 6 sticks will perform better than 8.

 

[flyproductions]

You got lucky there, some quad rank RAM works at 1066MHz,...

Sure i was. And i didn't try this on purpose. I ordered from a Chinese seller on ebay unaware of the whole rank-thing. But i got six absolute identical sticks like the one in the picture and they all work fine @ 1066.

But as they are somehow affordable, i ordered another six. 2R this time...

...low profile, running @ 1333, and did a lot of comparing from minimum (one stick) to maximum (six stick) configurations. Results, memory score in Geekbench as well as overall performance in Cinebench, were in a very narrow range but more often showing some small advantage for the configurations running @ 1066. Not enough to bas some recommendations on. But no one who, like me, "accidently" got working quad-rank-modules, ore has the memory running @ 1066 for other reasons should worry too much about lacking performance.

 

[tofa7a]

I am planning on upgrading the RAM on my 5,1. I was thinking about one of two options:

Option 1: 6x16GB totaling 96GB
Plus: utilizing 6 slots. Not sure if it is important though.
Negative: if I plan on upgrading in the future, then I have to upgrade all RAMs

Option 2: 3x32GB totaling 96GB
Plus: I can add in the future another 3x32GB
Negative: not sure if utilizing 3 slots vs 6 makes any difference.

Any thoughts?

 

[h9826790]

Option 2: 3x32GB totaling 96GB
Plus: I can add in the future another 3x32GB
Negative: not sure if utilizing 3 slots vs 6 makes any difference.

Don't go 32GB DIMM. Even we can make it work, but IMO, that's still at experimental level. Unless you just want to do it for fun, better avoid it at this moment.

 

[tofa7a]

Don't go 32GB DIMM. Even we can make it work, but IMO, that's still at experimental level. Unless you just want to do it for fun, better avoid it at this moment.

Thanks, @h9826790! I will do the 6x16gb.