Why don't X54xx work in 1,1/2,1?

Discussion in 'Mac Pro' started by applereviewguy, May 27, 2014.

  1. applereviewguy macrumors regular

    Aug 22, 2011
    I just bought some X5365's (scored them in a lot of 10 processors for $100, about $70 worth of processors leftover), and I was wondering why the Harpertown chips don't work in our machines?
  2. NOTNlCE macrumors 6502a


    Oct 11, 2013
    DMV Area
    The issue is in the logic board. There has been extensive research (such as HERE) into why they do not work. The final conclusion was "it's an Apple incompatibility." The FSB, Chipset, and Socket is not the issue since Intel's 5100 chipset can technically use 54XX CPUs, there are E54XX CPUs with a 1333MHz FSB (which is the same as your X5365s) and both use Socket 771. So honestly, there is "no good reason," if you ask me. It's just a logic board incompatibility.
  3. Umbongo macrumors 601


    Sep 14, 2006
    Needs a firmware update which will never exist.

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