Ram for 5,1: 2RX4??

[kkinto]

Hi,
I am looking to add some ram to my cMP from server monkey, 1x8GB (replace dead existing one) and 2 x 16GB dimms.

The 8GB dimm lists a spec with "2RX4" as the "Dimm Rank" and the 16's are listed as "Nno" for the same category.

Are these compatible? Is the 2RX4 spec a material thing in allowing these guys to work together?

At the moment all the 8GB currently installed in my Mac (5 of them, 40GB) are all marked as 2RX4.

Thnx

 

[octoviaa]

Hi,

I have never seen 'Nno' as DIMM RANK 2R means dual rank while 4R quad rank.

Try to look the one with 2R, like the one I bought below:
https://www.ebay.com/itm/For-Micron...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I'm using it along with 8GB modules, so my RAM configuration is: 2x16GB + 6x8GB == 80GB.

Usually 16GB modules still easy (and affordable) to find dual rank (2R) module, unless you're looking for 32GB then the dual rank is harder to find (usually more expensive too).

Side note:
BTW your 8GB modules speed is 12800R which has faster data transfer spec than mine: 10600R, however Mac Pro 5,1 can run max at 10600R speed (1333Mhz), so unless you're getting the same or lower price than 10600R it is not worth to spend extra for 12800R.

Cheers