How many cores remain idle in most applications?

Discussion in 'Mac Pro' started by Riwam, Feb 7, 2014.

  1. Riwam macrumors 6502a


    Jan 7, 2014
    Basel, Switzerland
    I am not a Pro and try to learn in this forum which nMP would be best for me. I can only afford either the 4 or at the most the 6 core and intend to keep it as long as possible. I had previously a Mid 2010 8-core MP sold to finance a new MP.
    What I do not understand is the fact that I read that most software will have to be adapted to make use of multicores nMP. This means that with few exceptions most cores remain presently idle. I read that at the present times most of the software actually uses 1 to 2 cores.
    Since from the first MP of 2006 to the last "old" MP of 2012 the number of cores increased from 4 to 12! is it possible that Apple built and sold to Pros computers that in most cases had too many unnecessary cores?
    The different tests mentioned in this forum, even without the already optimized FCP do show much better results in most cases when nMP with more cores are compared to nMP with less cores. This seems logical since why build and offer more expensive machines if the user has no benefit ?
    The feared reduction in the processor speed does not seem to apply as long as the same number of cores is actually working. Only the cache increases.
    Therefore I would be very grateful if knowing members help me to understand what seems to be a contradiction between most applications satisfied with 1 or 2 cores and Apple building more and more cores.
    Thank you very much in advance!!!
  2. linuxcooldude macrumors 68020

    Mar 1, 2010
    Because most software does not really need that much power. If your reading email, browsing the web and so on.

    Its really meant for specific, key applications that need that much power. Video editing, 3D animation, scientific computation, ect. Those types of software will most likely be built around and centered for computers that utilize multi-core, GPU type work.

    You said your not a professional, which maybe why your asking this question. Perhaps with such a computer you can't utilize it to its full potential because you don't have need for one.

    Of course there may be a lot of people who are not pro's but still enjoy such a computer anyway. But I don't understand if they complain if they are not using it for what it was intended to be used.
  3. Anim, Feb 7, 2014
    Last edited: Feb 7, 2014

    Anim macrumors 6502a


    Dec 16, 2011
    Macclesfield, UK
    What linuxcooldude said.

    But you can see for yourself by clicking spotlight and running "Activity Monitor"

    When Activity monitor is open, click the "Window" Menu and select "CPU History" and "CPU Usage"

    This opens up a small window showing active cores and their usage over time along with a meter to show realtime CPU load. Now run your app / game or whatever and watch the graphs.

    You can also manage the speed of the history graph by clicking "View"->"Update Frequency"

    Note that the Green blocks are application usage and the red blocks are OSX usage.

    Here is my little 2007 dual core iMac running while typing this out (also opened photo booth to cause some CPU usage)

    Edit: Also, consider the frequency that a CPU runs at.

    Attached Files:

  4. AidenShaw macrumors P6


    Feb 8, 2003
    The Peninsula
    Headroom for multi-tasking

    Additional cores also let you run multiple applications without them slowing each other down.

    This lets you surf or check email while rendering, without the the browser or mail client feeling slow.

    The system also runs lots of background processes. Multi-core keeps these tasks from slowing down the main applications.
  5. linuxcooldude macrumors 68020

    Mar 1, 2010
    Good point that I forgot about. You can see immediate results, using multiple software not using multiple cores.

    I quite frequently have to use a lot of software applications at once without being optimized for multiple cores and it works great without any slowdowns.
  6. A8NSLIDELUXE macrumors newbie

    Jan 28, 2014
    Is there any benchmark comparing 4c and 6c nMP?
  7. VirtualRain macrumors 603


    Aug 1, 2008
    Vancouver, BC
  8. Riwam thread starter macrumors 6502a


    Jan 7, 2014
    Basel, Switzerland
    It has nothing to do with complaining but with understanding.... and marketing

    Thank you for your kind answer and thank you for the other answers given to my question by the other helping member in this forum!
    I do appreciate all of you very much!
    I will never think of complaining if I buy a nMP and will certainly be very happy!!!
    My question was about the sense of providing hardware with many cores ( 6 to 12 ) while most software, even a decade or so after multicore processors spread over the world, still in its great majority makes no use of so many cores.
    I accept the arguments brought here by an experienced user that
    a) background processes also take place and need the work of the processor.
    b) several non multicore applications can in this way be run at the same time without slowing the computer.
    However since nMP with 8 and 12 cores ( as well as PCs with so many cores ) will remain a microscopic percentage of all computers in the world, in their vast majority providing nowadays 2 to 4 cores, why would software makers like for instance Adobe or Quark make any expensive effort to adapt their applications to more than 4 cores, as often suggested in this forum that will be the case?... Won't they rather go for what can be used by most customers in the world and brings them more money?
  9. AidenShaw macrumors P6


    Feb 8, 2003
    The Peninsula
    Two reasons:
    1. Some of the software can use many cores, and people who make their livings running that software don't like waiting.
    2. If they don't optimize for multi-core, some other company will and their best customers will leave for the faster product.

    Linuxcooldude basically said this in post #2.
  10. casperes1996 macrumors 68040


    Jan 26, 2014
    Horsens, Denmark
    Because professional software will use it

    They'll make the software that makes them the most money, yes, but that would be the highly multithreaded (using multiple cores) versions, since it gains them foothold with professionals who need it, besides the professionals are the ones who buy these 12 core machines. If they stopped optimizing for many cores, there apps would get bad press, and no use from professionals with access to many core systems, which would produce lower sale numbers from average users as well, since you are keen to believe the opinion of the professional is probably the best one. Furthermore, i7 chips, even if they are just 4 cores, can run 8 threads at the same time (intel hyper threading), meaning that optimizing for an 8 core CPU (not utilizing the hyper threading of the 8 core) will have positive effects on both 4 core and 8 core systems. (The 8 core running the app in a truly parallel mode, the 4 core adapting each core to whatever thread is the best all the time).

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