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SuperMatt

Suspended
Original poster
Mar 28, 2002
1,569
8,281
I saw this review of 2 different 64 GB RAM upgrades for the nMP. It includes benchmarks, so I thought it might be of interest to those frequenting this forum.

http://www.tekrevue.com/2013-mac-pro-ram-upgrade/
 

Stephent

macrumors member
Jan 31, 2012
92
0
Using the same one, decided to go with 48gb (3x16gb of DDR3-1866) since it's fastest if you don't need the full 64gb.

Only problem with that is that you can't go to 64GB if you want late without buying 4 new sticks. It is recommended that all the 16GB sticks come from the same lot. Just an fyi if you were not await of that.
 

Umbongo

macrumors 601
Sep 14, 2006
4,934
55
England
Only problem with that is that you can't go to 64GB if you want late without buying 4 new sticks. It is recommended that all the 16GB sticks come from the same lot. Just an fyi if you were not await of that.

You don't need to worry about that if the modules have the same specifications. As long as they have the same voltage and are of the same type (unbuffered/registered) they are likely to work together, although generally the more difference they have the less-optimal performance will be.

RAM kits using only identical DIMMs from the same vendor's production run only starts to matter when you are overclocking memory. It should not be an issue at all with workstations, thats why we have specifications.
 

Stephent

macrumors member
Jan 31, 2012
92
0
You don't need to worry about that if the modules have the same specifications. As long as they have the same voltage and are of the same type (unbuffered/registered) they are likely to work together, although generally the more difference they have the less-optimal performance will be.

RAM kits using only identical DIMMs from the same vendor's production run only starts to matter when you are overclocking memory. It should not be an issue at all with workstations, thats why we have specifications.

I'm just repeating what has been recommended. If I am spending that much money on RAM I wouldn't want to take the chance. Especially if I'm already ordering three sticks.
 

ChuckBlack

macrumors member
Jul 5, 2010
81
1
I'm looking at only going to 32GB of RAM for my nMac Pro when it arrives. That Hynix RAM seems like a great deal. I'm just wondering what would be better performance wise. 4x8GB or 2x16GB? There is mention of possibly taking a performance hit if I went with 2x16GB now and added another 2x 16GB in the future. Is that a huge worry? I'm leaning towards the 2x 16GB.

Thanks!
 

AidenShaw

macrumors P6
Feb 8, 2003
18,667
4,676
The Peninsula
I'm looking at only going to 32GB of RAM for my nMac Pro when it arrives. That Hynix RAM seems like a great deal. I'm just wondering what would be better performance wise. 4x8GB or 2x16GB? There is mention of possibly taking a performance hit if I went with 2x16GB now and added another 2x 16GB in the future. Is that a huge worry? I'm leaning towards the 2x 16GB.

Thanks!

Go with the 2x 16GiB.

The Xeon E5-xxxx v2 CPUs have huge L3 caches. Most apps mostly fit in the caches, and don't see significant performance hits even with a single DIMM configuration.

If you want to look at some data that supports this opinion, read https://forums.macrumors.com/threads/1704700/ start to finish.

If money were not a consideration, go with the 4x8 and throw them away when you upgrade. For me - I buy systems with 24 DIMM slots and always buy DIMMs in multiples of 8 to populate all channels.
 

ChuckBlack

macrumors member
Jul 5, 2010
81
1
Go with the 2x 16GiB.

The Xeon E5-xxxx v2 CPUs have huge L3 caches. Most apps mostly fit in the caches, and don't see significant performance hits even with a single DIMM configuration.

If you want to look at some data that supports this opinion, read https://forums.macrumors.com/threads/1704700/ start to finish.

If money were not a consideration, go with the 4x8 and throw them away when you upgrade. For me - I buy systems with 24 DIMM slots and always buy DIMMs in multiples of 8 to populate all channels.

Thanks for the link! Very informative. I think I'll go with the 4x8GB as I'm just a hobbyist that doesn't really need 64GB, I just wanted to be more future-proof by leaving two slots open. The difference in the multicore score with 2 banks filled vs 4 banks tips the scales for me. I'm planning on selling this machine in 2.5 years before Apple Care gives out anyway.
 
Last edited:

AidenShaw

macrumors P6
Feb 8, 2003
18,667
4,676
The Peninsula
Thanks for the link! Very informative. I think I'll go with the 4x8GB as I'm just a hobbyist that doesn't really need 64GB, I just wanted to be more future-proof by leaving two slots open. The difference in the multicore score with 2 banks filled vs 4 banks tips the scales for me. I'm planning on selling this machine in 2.5 years before Apple Care gives out anyway.

The real takeaway from those tests is that only two programs (one of them a synthetic benchmark that does no useful work) had large performance boosts from more DIMMs. If you pull those two out of the averages, the performance is virtually the same regardless of the number of DIMMs.
 

iPadPublisher

macrumors 6502
Apr 14, 2010
477
71
FWIW running 64GB of the Crucial, picked it up from Amazon, and its been fine for the first week I've had the machine.
 
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