4GB DIMMs show as 2GB on Mac Pro

Kilobyte Kid

4GB DIMMs show as 2GB on Mac Pro

[ Edited ]

I've had added two 4GB Crucial DIMMs to my Mac Pro for a couple of years now. Very reliable. All of a sudden, instead of reporting 10GB total (2GB stock + 2*4GB), it now only reports 6GB total. System information shows these as 2GB DIMMs instead of 4GB!

 

DIMM Riser B/DIMM 1:

 

  Size:2 GB

  TypeSmiley Very HappyDR2 FB-DIMM

  Speed:800 MHz

  StatusSmiley SurprisedK

  Manufacturer:0x80CE

  Part Number:0x000000463732353142363245353830304600

 *removed personal information*

 

DIMM Riser B/DIMM 2:

 

  Size:2 GB

  TypeSmiley Very HappyDR2 FB-DIMM

  Speed:800 MHz

  StatusSmiley SurprisedK

  Manufacturer:0x80CE

  Part Number:0x000000463732353142363245353830304600

*removed personal information*

 

 

I ran memtest86 on my system, and it completed without errors, but also reported only 6GB total. I opened my case, pulled out the riser card with the two 4GB DIMMs on it, reseated the DIMMs, and reseated the riser card. No change.

 

Any ideas?

 

Thanks,

Mark

1 Reply
Community Manager

Re: 4GB DIMMs show as 2GB on Mac Pro

Hi mrichman,

 

First of all I'm sorry to hear that you are having problems with your memory.

 

It sounds like your system is reporting the wrong information which could be down to a faulty memory module.  I would recommend trying each memory module one at a time in the system with no other memory installed.

 

This is the best way to check if a memory module is faulty and causing the issues you are having.  If one of the modules does not work on it's own we can arrange an exchange for you.  All our memory has a life time warranty so arranging an exchange can be done quickly for you.

 

All you have to do is contact customer service for your region using the links in my signature.  If you need any other help of advice please don't hesitate to ask and I would be happy to help.

Crucial_Junket, Crucial Moderator, UK


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