HELP - Ram issues!!

[uMac]

I recently got 8GB of ram (4x4GB) and Put them in the risers as so. But my computer will not seem to acknowledge 2 of the sticks as 2GB, but rather one...

Now I played a bit of musical ram but the computer will only see 7GB out of the 9 (so a set of 2GB shows up as 1GB). I think 1 stick may be only 1GB or is this a computer issue? I would like to know as I will send the two chips back I think are the cause of this if its Ram and not some 'Mac Pro' thing.

Is there a way to test the ram?

Thanks so much for any help you can give.

Riser A

2GB - New (Currently Mac thinks it 1GB)
2GB - New (Currently Mac thinks it 1GB)
512GB - Original
512GB - Original


Riser B
2GB - New
2GB - New
Empty
Empty

 

[krye]

You configuration looks good. You made sure that you purchased the right speed? (800MHz for Jan 08 Mac Pros and 667MHz RAM for 2007 Mac Pros)

I'd test them one pair at a time to rule out the possibility that the 2G sticks are not really 1G sticks.

Do they all look the same? Are the pairs easily distinguishable? In other words, you're not mixing in the 512s with the 2Gs by accident?

Maybe take the heat sinks off and see if there is a label somewhere under there that states the size.

 

[uMac]

Do they all look the same? Are the pairs easily distinguishable? In other words, you're not mixing in the 512s with the 2Gs by accident?

All the packaging looks correct (Size and Speed) and I am not mixing the 512 with the 2GB as they have different brand stickers.

I will try your suggestion of testing them 1 pair at a time.
Any more suggestions appreciated.

 

[surflordca]

All the packaging looks correct (Size and Speed) and I am not mixing the 512 with the 2GB as they have different brand stickers.

I will try your suggestion of testing them 1 pair at a time.
Any more suggestions appreciated.

Pull out the 512's and see if the computer sees the others at 2 GB.

 

[uMac]

Pull out the 512's and see if the computer sees the others at 2 GB.

Doesn't help

 

[kittiyut]

Did you try moving the two on the top riser (that mac thinks they are 1 GB) to the bottom riser and see if it still report as 1GB (on the bottom)? If so, then you really do have 1GB sticks instead of 2GB !!!