After 4.1 to 5.1 update - MP ram shows up as 1333mhz?

Discussion in 'Mac Pro' started by mluters, Sep 5, 2012.

  1. mluters macrumors member

    Jan 25, 2010
    I upgraded my 4.1 quad core 2.66ghz MP to a 5.1 hex core 3.46ghz about 8 months ago and I have had 24gb 1066mhz ram from OWC in for about one year. The ram has always showed up as 1066mhz ram regardless of I just updated to ML 10.8.1 and suddenly the ram shows up as 1333mhz?

    I know there are posts about placing 1333mhz ram in 5.1 MP's and it only showing up as 1066mhz, but I have the opposite 1066mhz ram is showing up as 1333mhz. Any ideas what's going on here?

  2. PowerPCMacMan macrumors 6502a


    Jul 17, 2012
    PowerPC land
    Hi, perhaps mountain lion tweaks the ram to report 1333. The only way the system can report the 1333 MHz is if the processor supports it. With that said, the quad 6-core w3690 or 3,46 GHz chip automatically supports the highest speed of the memory, namely 1333. If the memory originally is 1066 MHz only, could be a dual MHz based set of RAM. Really weird though as the only way it would report 1333 is if the processor supports it and the 5,1 firmware of the 2010 does, while 4,1 does not.

    not sure, but it could be mountain lion related. Somehow your 1066 is being reported at the highest memory speed.
  3. Umbongo macrumors 601


    Sep 14, 2006
    The answer could be OWC sold you 1333MHz memory and everything is working as it is supposed to and wasn't before. Send of the part and serial numbers to them and ask them to check.
  4. mluters thread starter macrumors member

    Jan 25, 2010
    Just a quick follow up:

    I talked with OWC tech support and they said...Apple has updated (in ML) how the system profiler reads ram configuration and now it's correct in reporting system ram. He also stated that the ram I got from OWC must have been 1333 mhz and not 1066 mhz because now it shows up as 1333 mhz ram.
  5. DanielCoffey macrumors 65816


    Nov 15, 2010
    Edinburgh, UK

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