Mac Pro / Lion 10.7.4 build 11E53 memory reporting

[michael_aos]

I upgraded my 2006 Mac Pro 1,1 to 16GB back in February. Added 4x 2GB DIMM's from OWC.

It had been reporting 16GB until recently. This morning, I noticed that 2 of the DIMM's are reporting as 1GB instead of 2GB.

DIMM Riser B/DIMM 3:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D3339355435373530435A342D4345363120
Serial Number: 0x5006909C

DIMM Riser B/DIMM 4:

Size: 1 GB
Type: DDR2 FB-DIMM
Speed: 667 MHz
Status: OK
Manufacturer: 0x80CE
Part Number: 0x4D3339355435373530435A342D4345363120
Serial Number: 0x0208E89D

They still show as "OK" in Lion, and are correctly identified as 2GB under Snow Leopard.

I'm kind of wondering it the issue is really just a reporting bug and not a problem with the RAM.

 

[nambuccaheadsau]

Have similar upgraded Mac Pro 2.1 with 16GB memory. When first installed this is precisely what happened with reporting, but after a few weeks this settled down to always shows 16GB. Think it is a reporting error only.

Also noticed this when switching back from Windows 7 using Bootcamp.

 

[michael_aos]

I swapped the DIMM's from slots 3 & 4 with the ones from 1 & 2.

Now it's reporting 16GB again...