Mac Pro 5,1 Ram Not recognized - Please Help

[Robsalazar]

Hi, I have A Mac Pro 5,1 single cpu which I upgraded to a Westmere X5690 3.46 6 Core processor .
A couple of days ago my computer crashed. A week later I realized that instead of the 4 Ram Dimms (4gb each) my computer only recognized three of them. So I uninstalled the RAM DIMMS and installed them again. And to my surprise it now only recognizes two DIMMS.
So I repeated the process of uninstalling and installing and now it only recognizes one!

Whats wrong?

 

[barbu]

It's probably no help but when I had a Pro 1,1 it was very finicky about memory and I had to arrange and re-arrange the chips in different slots until it (mostly) worked properly.