Max RAM

h9826790

macrumors G5
Original poster
Apr 3, 2014
12,960
5,845
Hong Kong
I have a question about max RAM.

No matter W3520 or W3690, both clearly state that they only support 24G of RAM, why my Mac Pro 4,1 Quad can run 32G of RAM or even more?

Is that just a max demostrated result from the factory, but the not real limit?

Otherwise, I couldn't undertand why my machine can handle more RAM than the CPU limit.
 

MH01

Suspended
Feb 11, 2008
12,118
9,216
I have a question about max RAM.

No matter W3520 or W3690, both clearly state that they only support 24G of RAM, why my Mac Pro 4,1 Quad can run 32G of RAM or even more?

Is that just a max demostrated result from the factory, but the not real limit?

Otherwise, I couldn't undertand why my machine can handle more RAM than the CPU limit.
64gb for single CPU , 96Gb for dual CPU.

My understanding is the OS limit is 96gb, not sure if that has been changed in mavericks.
 

AidenShaw

macrumors P6
Feb 8, 2003
18,130
4,200
The Peninsula
I have a question about max RAM.

No matter W3520 or W3690, both clearly state that they only support 24G of RAM, why my Mac Pro 4,1 Quad can run 32G of RAM or even more?

Is that just a max demostrated result from the factory, but the not real limit?

Otherwise, I couldn't undertand why my machine can handle more RAM than the CPU limit.
Sometimes the specs reflect what was possible when the system or CPU was released, but later higher density but compatible DIMMs come out and larger memories work. The specs aren't updated, because that requires testing and validation.

I'm typing from a Dell XPS 435MT with 24 GiB of RAM, even though the specs still say that is supports a max of 12 GiB. Some time after the system was released with 6 slots at a max of 2 GiB/slot some compatible DIMMs of 4 GiB came out. I have twelve of those 4 GiB DIMMs.