Mac Pro Ram problem need help

[mbimac]

I have no idea my mac pro always get some problem, today I have Rams problem need your help.Thanks

Early 2008 Mac pro 2x CPU 2.8Ghz 4core each, I have 2x1GB Rams(Factory come with system) I bought 2x2GB RAMs from 1-8004Memory.com. I am using these 2 rams for about 1 month and today got problem，when I only installed these 2 RAMs(2x2GB) the system only shows 3GB total sometime only shows 2GB (1GB each but it's 2GB ram) and only showing up Riser B slot 1&2. I 100% sure put each Ram(2GB) on both slot 1 Riser A&B.

When I try to follow mac pro Rams rule put factory Rams(2x1GB) on Riser A slot 1&2 and 2x2GB on Riser B slot 1&2 the system only gets 2GB from Riser B slot 1&2 other slots on Riser A & B are empty，what's going on here? Does any Rams has problem or what?

BTW first time I using RAMS on the wrong configration which I put 1GB+2GB on Riser A slot 1&2, same as on Riser B. I jsut realized yesterday that I did wrong way so when I try to follow the Mac pro Rams way but has troubles
any ideas? I think maybe my additional 2 2GB RAMS which I bought from third part have been damaged. I test in system all these 4 rams can pass(start while press D key for testing )

I attached 2 pictures the second one shows 2GB total 1gb each from Riser B slot 1&2 are my(2x2GB RAMS third part but they are OEM which are the same rams chip) why they only shows 1GB for each and my factory 2x1GB Rams on Riser A slot 1&2 are shows empty. I have 3 years apple care when I bought this 1.5 month ago,can I bring to apple store let fix for me I think I use the third part RAMs does it matter or not.thanks

Thank you for your time and help me to fix this problem.

 

[Billydelp4]

I have no idea my mac pro always get some problem, today I have Rams problem need your help.Thanks

Early 2008 Mac pro 2x CPU 2.8Ghz 4core each, I have 2x1GB Rams(Factory come with system) I bought 2x2GB RAMs from 1-8004Memory.com. I am using these 2 rams for about 1 month and today got problem，when I only installed these 2 RAMs(2x2GB) the system only shows 3GB total sometime only shows 2GB (1GB each but it's 2GB ram) and only showing up River B slot 1&2. I 100% sure put each Ram(2GB) on both slot 1 River A&B.

When I try to follow mac pro Rams rule put factory Rams(2x1GB) on River A slot 1&2 and 2x2GB on River B slot 1&2 the system only gets 2GB from Riser B slot 1&2 other slots on Riser A & B are empty，what's going on here? Does any Rams has problem or what?

BTW first time I using RAMS on the wrong configration which I put 1GB+2GB on Riser A slot 1&2, same as on Riser B. I jsut realized yesterday that I did wrong way so when I try to follow the Mac pro Rams way but has troubles
any ideas? I think maybe my additional 2 2GB RAMS which I bought from third part have been damaged. I test in system all these 4 rams can pass(start while press D key for testing )

I attached 2 pictures the second one shows 2GB total 1gb each from Riser B slot 1&2 are my(2x2GB RAMS third part but they are OEM which are the same rams chip) why they only shows 1GB for each and my factory 2x1GB Rams on Riser A slot 1&2 are shows empty. I have 3 years apple care when I bought this 1.5 month ago,can I bring to apple store let fix for me I think I use the third part RAMs does it matter or not.thanks

Thank you for your time and help me to fix this problem.

Put the 2x2gb on the top riser and 2x1gb on the bottom. Couldn't understand if that was how you had it or not.

also make sure they are all seated well in their slots.

Billy

 

[mbimac]

I put the factory 2x1GB on the upper Riser A and 2x2GB(18004memory) on the lower Riser B duo to mac pro RamReplacement Instructions

"Follow the instructions in this document carefully. Failure to follow these instructions could damage your equipment and void its warranty.
The Mac Pro (Early 2008) computer has two memory riser cards with a total of 8 memory slots. On each card, the slots are arranged as two banks of two slots each. The computer comes with a minimum of 2 GB of memory, installed as a pair of 1 GB fully buffered, dual inline memory modules (FB-DIMMs) in two of the DIMM slots. Additional pairs of 1 GB, 2 GB, or 4 GB FB-DIMMs can be installed in the open DIMM slots, as illustrated below. Maximum memory is 32 GB.
DIMMs must be installed as pairs of identical size and type, from the same vendor. In the illustration below, like-colored DIMMs must match."

btw are these Riser A and B are exactly same just upper and lower position? thanks