5 Replies Latest reply: Jan 31, 2013 5:03 PM by The hatter
Biggles2 Level 1 (60 points)

I recently upgraded my 2.66GHz 4 core Mac Pro 2006 to a 2.66 GHz 8 core. I am using 667MHz DDR2 ECC fully-buffered RAM but I see that when new the 8 core model used 1066MHz DDR3 ECC SDRAM which is less expensive.


Is it advisable to install the faster memory, will I harm the machine by doing so? Is there any advantage other than cost because I still have the orignal motherboard so supect that the RAM will only operate at 667 MHz?

Mac Pro, Mac OS X (10.7.2), 2 x 2.66 GHz 17 GB Ram, Radeon 5770
  • The hatter Level 9 (60,930 points)

    No yours needs DDR2, it does not support physically or from the cpu.


    DDR3 needs Nehalem processors


    You have to have FBDIMMs to fit your Risers


    These are great and what I and others use -



  • Biggles2 Level 1 (60 points)

    Thanks Hatter, appreciate  your reply.


    That is a great price. As long as I buy a pair that meet Apple sepcs I assume it is OK to have a mixture of sizes and suppliers.


    Presently I have 2 original 512 MB from Apple, 4 x 2GB from Trans Intl and 2 x 4 GB from Trans Intl. I want to switch out the smaller ones.

  • The hatter Level 9 (60,930 points)

    remove the 512s.


    test with just one brand. Then add one of the other types. There can be 'issues' mixing but the Amazon are as good or better than any of the 4 other brands incl. Apple's that I used in mine.


    And kick the fans up to 800 rpm can help with air flow.

  • dclayton Level 1 (40 points)

    I Checked out the amazon RAM but they will not ship to Canada and amazon.ca does not have that RAM.


    I will likely replace the 512s with 2x2GB from  trans intl. they have worked well up to now and then I will have al from one supplier. . Yes, I noticed that the RAM in salts 1 and 2 was getting warm, 75 deg C and I bumped up the fan .


    Thanks again.

  • The hatter Level 9 (60,930 points)

    borderline temp there, goid fbdimms should stay in 60-68, 75 was where I would see trouble... and those are 6yr old modules. newer ones should be better. nit worth just for 1GB anyway.