2 X Dual Core vs. 1 X Quad Core...

Discussion in 'Mac Pro' started by techybrad, Oct 3, 2009.

  1. techybrad macrumors newbie

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    Oct 3, 2009
    #1
    Having all other variables equal (same processor speed / RAM / VRAM / OS), what are the differences between MPs with 2 X Dual Core processors and those with 1 X Quad Core processor? Essentially, you get the same number of cores, but the 2 X Dual Core machines are seemingly less expensive. Is there any substantial advantage to the Quad Core processor? Any differences with expected longevity / durability? Thank you!
     
  2. psingh01 macrumors 65816

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    Apr 19, 2004
    #2
    Quad core should be faster because it can share data faster between it's cores instead of copying over to a separate processor's cache. Assuming the app is multicore/processor aware. Should not use up as much power either.
     
  3. tofagerl macrumors 6502a

    tofagerl

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    #3
    Also, quad just sounds better. Dual is sooo 2006.

    Seriously, no - there aren't any magical benefits.
     
  4. yanquis macrumors regular

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    Aug 26, 2009
    #4
    i didnt even know they had dual dual core machines...that said quad nehalem is quite a bit faster than any 2 x dual could be at the moment.
     
  5. gugucom macrumors 68020

    gugucom

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    #5
    Intel dropped the dual core Xenons for the Nehalem line and that means Apple had to follow. So if you have a 1 CPU Quad it is allways a 2009 machine. Dual CPU dual core was common in MP1,1 and MP3,1 with the Xeon X51XX and X52XX lines respectively.

    The older Xeon CPUs sure are less expensive because Nehalem added between 30-50% bandwidth and applied one die shrink which always saves energy. In terms of architecture Nehalem stands out for introducing QPI memory technology.
     
  6. kevink2 macrumors 65816

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    Nov 2, 2008
    #6
    The last dual core Mac Pros were the 2006 model. So comparisons would have to be between a dual core dual processor 2006 model and probably the quad core 2008. Which then had different memory. So there would probably be other differences. Unless there was a later model 2006 quad with a single core. This is before my Mac Pro time (I wasn't able to buy an Intel Mac until after the 2008 came out).

    In general, though, the differences in speed between the same number of cores, either on one processor die or spread between 2 processor dies, depends on several factors. For instance, early Intel quad cores were, I believe, essentially 2 physical core chips bound together. True quad core designs came later. Also, 2 separate physical chips versus 1 true quad core likely differs based on actual load. One multithreaded process spread over 4 cores, if they share data, would probably work better on a quad core due to better cache utilization. But 2 completely disjoint processes would probably work better on different physical cores, reducing conflicts on cache, etc.
     
  7. jwt macrumors 6502

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    Mar 28, 2007
    #7
    Agreed. I guess which is better depends on what kind of process you're trying to run. If you have something that is multithreaded and can very effectively utilize a single processor's cache, then the single quad might be best. But if you have two completely separate processes or something requiring huge data streams, then spreading those data things across two front-side busses (neglecting Nehalem) might be better.
     
  8. frimple macrumors 6502

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    #8
    This +1, though technically the 2008 could be a single Quad.
     
  9. thermodynamic Suspended

    thermodynamic

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    #9
    http://www.macworld.com/article/139507/2009/03/macpro2009.html

    http://www.macworld.com/article/139919/2009/04/cto_macpro.html

    Depending on app, 8-core systems DO offer much more in terms of real-life performance, but those are few and far between, not to mention the cost. Those high-end units are for a niche audience; the Xeon single-quad units easily being the best bang for the buck. (Even going from 2.66 to 2.93GHz on the single quad; it's just numbers. Save the $500 for a better video card and more RAM...)
     
  10. gugucom macrumors 68020

    gugucom

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    #10
    I don't think so. Apple did not sell a single socket LGA771 Quad (pre 2009). They could theoretically have done it from 2007 when the X53XX Clovertown line was available and later the X54XX Harpertown in 2008 but they had no single socket LGA771 logic board. And Intel designated the Xeons as dual socket CPUs. So they choose to stay away from that configuration. So if you are offered such a machine it is customer configured. The single socket Quads are all LGA1366 from 2009.
     
  11. kevink2 macrumors 65816

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    Nov 2, 2008
    #11
    I recall the quad core 2008 being $500 cheaper than the 8 core 2008. Yes, it wasn't a "base" configuration, but a BTO option. And, unlike the current generation, it was at least theoretically possible to add a CPU later if you found one.
     
  12. gugucom macrumors 68020

    gugucom

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    #12
    Unless I'm very much mistaken that "Quad" was a 2x Dual Core configuration. Updates were of course possible via replacement of two X52XX Wolfdale CPUs for two X54XX Harpertown CPUs.

    I did a similar thing with a 2,66 GHz Woodcrest to a 3,0 GHz Clovertown.
     
  13. Infrared macrumors 68000

    Infrared

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    Mar 28, 2007
    #13
    I wasn't sure myself, but I found the list of 2008 processor configurations here:

     
  14. gugucom macrumors 68020

    gugucom

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    #14
    Kudos to kevin2k and infrared. I was wrong on that call. So Apple did not have a single socket logic board and left one socket empty it appears. Good value for money in those upgrades.
     
  15. Umbongo macrumors 601

    Umbongo

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    Location:
    England
    #15
    It was a nice option to have ($1,999 refurb!) but it seemed most people went with the 8 core models. While you saved $500 and still had the option to add a processor you lost a $100 heatsink and $800 processor.
     
  16. kevink2 macrumors 65816

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    Nov 2, 2008
    #16
    One of the reasons people got upset with Apple with their 2009 models. No upgrade path for the single quad configuration with an additional CPU a couple years later if desired.

    I just bought more than I really needed 1 1/2 years ago, "future proofing", in other words. Only time will tell whether I messed up going 8 core or not. 4 cores is still all that I really need. Hard drive speed is my limit right now at times.
     

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