2.66 GHz Nehalem 4 core vs. early 2008 2.8 GHz 4 core?

Discussion in 'Mac Pro' started by Jason Bourne, May 9, 2010.

  1. Jason Bourne macrumors member

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    Dec 9, 2005
    #1
    Considering purchase of a used Mac Pro. The choices are basically:
    - Early 2009 Nehalem 4 x 2.66GHz with NVIDIA GeForce GT 120 512MB
    - Early 2008 4 x 2.8 GHz with NVIDIA GeForce 8800 GT 512 MB

    What speed difference would you expect to see between the two on CPU and graphics (games, photoshop, lightroom) tasks?

    What if the latter was an 8 core instead of a 4 core? Where do you see the big boost from the extra 4 cores? Is it noticeable in lightroom/photoshop type tasks or only on really heavy lifting stuff such as 3D rendering and video encoding?
     
  2. Hellhammer Moderator

    Hellhammer

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    #2
    2009 Nehalem is faster due newer architecture and Turbo Boost. 8-core might be faster for video encoding depending on what app you use.
     
  3. Eithanius macrumors 65816

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    Nov 19, 2005
    #3
    Was there even a 4-core Mac Pro Harpertown back in 2008 to start with...? :confused:

    Harpertown Mac Pros were all in 8-core variants, 2.8, 3.0, and 3.2GHz...
     
  4. Hellhammer Moderator

    Hellhammer

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    #4
    http://support.apple.com/kb/SP11

    There was quad core 2.8GHz which was a BTO
     
  5. Jason Bourne thread starter macrumors member

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    Dec 9, 2005
    #5
    Most of the 2.8 harpertowns on ebay do tend to be 8 cores. I assume that a 4 core 2.66 nehalem would still be faster for the majority of tasks than an 8 core 2.8 harpertown? Am I correct?
     
  6. Hellhammer Moderator

    Hellhammer

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    #6
    Yes, because only few apps can take advantage of 8-cores. 8-core is more "future-proof" though as it has more RAM slots and sooner than later apps will support 8 cores
     
  7. VirtualRain macrumors 603

    VirtualRain

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    #7
    I wrote this recently in another thread on this subject which may help explain the benefits of the 09 vs 08...

    As for the 2009 vs. 2008... the 2008 is the last of the FSB architecture and good-ridance to that. The FSB runs at 200MHz and is quad-pumped to achieve 800 MT/s. The FSB is used for interprocessor communications and also for both CPU's in a DP system to communicate with the memory controller. The 2008's also used an 800MHz memory bus with fully buffered DDR2 which can as much as double latency (source). The only real advantage to FBDIMM's is that it allows lots of memory DIMM sockets since trace lengths to the controller from the DIMM sockets are no longer relevant to the design (since the data is fully buffered) - but you sacrifice a lot of performance to get those plentiful DIMM slots.

    Architecturally, the 2009 Nehalems bring a lot of advancements to the table starting with the elimination of the FSB. Now interprocessor communications happen over a quick path interconnect at 8x the speed of the old FSB (6.4GT/s) and the memory controller is now on-die with each CPU having direct access to it's RAM bank or a QPI link away to the RAM on the other processor. No more contention for memory access by CPU's competing for cycles on the already bottlenecked FSB that's in the 2008's. Add to this support for 1066MHz DDR3 in triple-channel mode, and the memory performance is almost on par with the L3 cache bandwidth of the 2008 CPU on-die cache!

    Then there's hyperthreading which uses stalled cycles on each core to process other tasks that are queued up and ready to go... so as not to waste any clock cycles when the CPU is maxed out.

    Last but not least, there's Turbo Boost, which provides a clock multipler boost to one or two cores for lightly threaded apps when the other cores can be put into a lower power state.

    Now all this technological advancement is unfortunately untapped by most software applications but highly threaded memory intensive software has been proven to perform better on the Nehalem architecture and this gap will only increase over time as software is optimized for it.

    Can everyone leverage the benefits of the 2009 architecture? Of course not. But everyone will benefit from at least some of these new enhancements at some point in their workflow.

    The fact is that there are few, if any, technological merits to the 2008 architecture. Only it's price/value is attractive because most of our software (but not all) pitifully trails the capabilities of current hardware.
     
  8. Jason Bourne thread starter macrumors member

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    Dec 9, 2005
    #8
    Thanks everyone. I'm going to go with the used Nehalem as it seems to provide the best performance and is more future proof. It should be plenty for my needs.
     

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