I ordered a set of 3x 16GB RAM modules from OWC and asked in advance explicitly whether it would work in my 2009 Nehalem Mac Pro 4.1 (2x 2.66Ghz), a machine I had ordered directly from Apple the day it came out and never upgraded since. All original, no hacks.
OWC said yes.
Yet neither all 3 at once nor just one in the 1st socket worked. They do get warm though and seem placed properly.
Before I had tried two other brands of 1066Mhz server RAM that the ebay sellers insisted would work but also didn’t. So I wanted to be safe and chose OWC.
This machine does work with the 3x 2GB RAM it shipped with.
So the Mac Pro seems fine. Socket 1,2,3 work well.
The OWC RAM does work in my 2010 Mac Pro 5.1.
So the RAM seems fine too.
They just don’t work together.
When turning on the machine, the screen stays black and the power light blinks immediately,
I sent the set of 3 sticks back to OWC and they confirmed it works in a 2009 Nehalem Mac Pro, they say they tried them again to verify.
Q:
What could be the issue and would this be caused by the Nehalem processors, therefore not be a problem anymore, if I replace them with later processors?
Note:
One thing I noticed is that the official requirement is that the RAM has 1066Mhz and the sales page as well as the order confirmation email say so but on the actual RAM sticks it says OWC1333D3MPE16G containing the number 1333 and not 1066. I asked them about it and they said it basically means nothing.
I already did the PRAM Reset at boot (Opt+Cmd+P+R) with the original compatible and the OWC non-compatible RAM.
I did not mix and match or anything like that. Three identical RAM units only in socket 1,2,3.
To sum up:
The OWC RAM does work in my other machine.
Some RAM works in this machine, some other 1066Mhz RAM that is supposed to, also doesn’t work in this machine.
OWC item description:
48.0GB OWC Matched Set (3x 16GB) PC-8500 1066MHz DDR3 ECC SDRAM Modules for Mac Pro Early 2009 & Late 2010 'Nehalem' & 'Westmere' systems & Early 2009 Xserve.
OWC said yes.
Yet neither all 3 at once nor just one in the 1st socket worked. They do get warm though and seem placed properly.
Before I had tried two other brands of 1066Mhz server RAM that the ebay sellers insisted would work but also didn’t. So I wanted to be safe and chose OWC.
This machine does work with the 3x 2GB RAM it shipped with.
So the Mac Pro seems fine. Socket 1,2,3 work well.
The OWC RAM does work in my 2010 Mac Pro 5.1.
So the RAM seems fine too.
They just don’t work together.
When turning on the machine, the screen stays black and the power light blinks immediately,
I sent the set of 3 sticks back to OWC and they confirmed it works in a 2009 Nehalem Mac Pro, they say they tried them again to verify.
Q:
What could be the issue and would this be caused by the Nehalem processors, therefore not be a problem anymore, if I replace them with later processors?
Note:
One thing I noticed is that the official requirement is that the RAM has 1066Mhz and the sales page as well as the order confirmation email say so but on the actual RAM sticks it says OWC1333D3MPE16G containing the number 1333 and not 1066. I asked them about it and they said it basically means nothing.
I already did the PRAM Reset at boot (Opt+Cmd+P+R) with the original compatible and the OWC non-compatible RAM.
I did not mix and match or anything like that. Three identical RAM units only in socket 1,2,3.
To sum up:
The OWC RAM does work in my other machine.
Some RAM works in this machine, some other 1066Mhz RAM that is supposed to, also doesn’t work in this machine.
OWC item description:
48.0GB OWC Matched Set (3x 16GB) PC-8500 1066MHz DDR3 ECC SDRAM Modules for Mac Pro Early 2009 & Late 2010 'Nehalem' & 'Westmere' systems & Early 2009 Xserve.
