I just bought a used MacPro3,1 on Amazon. The system came with Mac OS X 10.6 but I downloaded Yosemite and it states that one of the 2GB modules is faulty.
When I installed Yosemite it wiped out diagnostics for Apple Hardware Test (AHT) but this isn't a big deal as it can be downloaded and booted from USB for particular Mac models. When I ran the AHT in extended testing mode (a test that runs for two hours) it states that I don't have any issues:
The new RAM came in, and I put it in in place of the bad RAM, and the same spot is still showing the EEC errors. The replacement RAM I was sent had a different number on it then the rest of the RAM, but I'm starting to think it isn't the RAM, it's maybe the Reiser. Can anyone confirm this? Can this damage the RAM? However sometimes, it boots and doesn't have an issue with the RAM. I'm starting to think it has something to do with sleep mode.
Okay so it's definitely the Riser. I swapped Risers, and waited a little bit and now it's reporting it on the other Riser.