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macrumors newbie
Original poster
May 17, 2013
2
0
Hey guys, new to the board, but long time follower. I have a question that has been bothering me for almost a year.
I have been able to install 2GB sticks (up to 8 for a total of 16GB) of PC2-6400F from random servers (HP, IBM, etc.) in a 2008 Mac Pro without a single issue.
But when I try to use 4GB sticks (also from random HP or IBM servers) of PC2-6400F, they are never recognized. All 4 of the red lights are on for each of the modules and the power LED blinks. No startup at all.
I have tried every memory configuration possible with no results. I have tried over a dozen different working pairs of matching 4GB sticks on 4 different 2008 Mac Pro's without any success.
Can anyone shed some light on this matter? I have searched and searched, but couldn't find anyone that has an issue like mine.
 

xcodeSyn

macrumors 6502a
Nov 25, 2012
548
7
But when I try to use 4GB sticks (also from random HP or IBM servers) of PC2-6400F, they are never recognized. All 4 of the red lights are on for each of the modules and the power LED blinks. No startup at all.
...
Can anyone shed some light on this matter? I have searched and searched, but couldn't find anyone that has an issue like mine.
The answer to your question is right in this post, any quad rank (4R) FB-DIMM modules won't work with the MP, but dual rank (2R) will. You should read the whole thread to see your options.
 

-PM-

macrumors newbie
Original poster
May 17, 2013
2
0
Thanks. That's exactly what I was looking for. Can't believe I missed that detail throughout my searches.
 
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