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amorph

macrumors newbie
Original poster
Oct 1, 2006
9
0
Hi, I bought a Mac Pro with 32GB (4x8GB) Ram and bought additional four 64GB modules myself. Now I tried to install the Ram according to this guide. From what I understand I should install the small modules into channel 1 (5 & 8) and channel 2 (3 & 10) and the bigger modules into channel 3 (1 & 12) and channel 4 (6 & 7). As stated for 8 modules channel 3 should be skipped so channel 5 (4 & 9) should be used instead.
I tried all the combinations, but nothing worked. I always get the amber light flashing when I switch on the Mac. As I have to open and close the case every time I try another combination this took a while and a lot of nerves. When I install either all the 4 smaller modules or the bigger ones everything is fine, so I thought the small and big modules does not work together, but there is a combination which is surprisingly working:

About This Mac 2020-01-15 15-48-03.jpg


But it's not working anymore when I try to install the 2 other 8GB modules.
Does anyone got mixed ram combination with 8 modules working?

Thanks a lot!
 
As the screenshot above proves both is RDIMM. And its working (partially) together. Just the combination with all 8 modules does not work.
 
I personally could never get 8 dimms to work Properly on my new Mac Pro. Funnily, 10 worked, even though it‘s not adviced and it dramatically lowered my geekbench multicore score by more than 2000 points.

Someone on the forum advised the correct order, and it was different than what apple states in that document.
Check this out, maybe it helps you somehow: LINK
 
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