PowerMac Processors

Discussion in 'Macintosh Computers' started by Don Cherry, Dec 24, 2004.

  1. Don Cherry macrumors newbie

    Dec 24, 2004
    Long Island, NY
    What is the difference between, let's say a 1.8GHZ single and Dual processor, besides the obvious?

    A Dual 1.8, is that two 900MHZ processors or two 1.8GHZ?

    What is the performance gap between these?
  2. Sun Baked macrumors G5

    Sun Baked

    May 19, 2002
    The SP PowerMac is a iMac in a PowerMac case -- so the single processor chipset (U3-Lite+Shasta) is the consumer chipset with the FSB running at a third of the CPU clock (600MHz.)

    The DP PowerMac has the dual CPU capable XServe/PowerMac chipset (U3H+K2+PCI-X Tunnel) run their FSB at 1/2 the 1.8 (900MHz) -- in addition the 2.0/2.5 have a faster HT bus and HT PCI-X Tunnel that the DP 1.8 doesn't include.

    The DP are basically twice as fast as the SP machines that take advantage of SMP -- and faster than the SP machines that don't because the OS will split threads between the two CPUs, so an monolithic app that hogs a CPU won't bring everything else to a crawl.

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