1. wes008's Avatar
    Title pretty much states it. I am wondering why companies are saying "1Ghz dual-core" without mentioning total of 2Ghz of power. Are the cores actually set at 512Mhz?

    P.S. Mods, if this is in the wrong section please feel free to move it. I couldn't think of any other forum to put it in, and it kind of fits since all current and near-future dual-core phones are running Android.
    02-28-2011 02:43 PM
  2. brillrick's Avatar
    Title pretty much states it. I am wondering why companies are saying "1Ghz dual-core" without mentioning total of 2Ghz of power. Are the cores actually set at 512Mhz?

    P.S. Mods, if this is in the wrong section please feel free to move it. I couldn't think of any other forum to put it in, and it kind of fits since all current and near-future dual-core phones are running Android.
    There are two 1 Ghz cores. I think you might not understand how the dual-core works. Just because it dual core it doesn't mean the phone runs 2 times faster.

    I don't have the ability to put in a link, but there is a white paper where NVIDIA explains how their dual core process works (copied from NVIDIA site):

    Symmetrical Multiprocessing (SMP)
    Symmetrical Multiprocessing technology enables mobile processors to not only deliver higher
    performance, but also meet peak performance demands while staying within mobile power
    budgets. A multi-core architecture with SMP is defined by the following characteristics:
    • Architecture consists of two or more identical CPU cores.
    • All cores share a common system memory and are controlled by a single Operating
    system.
    • Each CPU is capable of operating independently on different workloads and whenever
    possible, is also capable of sharing workloads with the other CPU.

    Imagine a mobile phone that has a dual core CPU with SMP support-- if the phone’s navigation
    application is running concurrently with a streaming audio application, the OS can assign the
    navigation task to one CPU core and the streaming audio task to the second CPU. Another
    example is a single multi-threaded application that can benefit from multiple CPUs. The OS can
    assign the threads to run on both CPUs concurrently and finish the task faster by sharing the
    workload across the two CPUs. Since the workload is split across the two cores, these cores
    can run at a reduced speed while achieving excellent performance and also conserving power
    (running at lower frequency lessens the voltage required, resulting in a reduction in power by
    the square of voltage decrease).

    To summarize with Dual-Core processors you could:
    1. Have one core running 1 app and another running a separate app and since the processor isn't running 2 apps at once, it uses less resources and power.
    2. If you are running 1 app, you could have one app handle one part of the app, while the other core handles another aspect of the app. For example, you could have 1 core loading the text of a webpage, while the other core loads in the flash animation part of the site. thus each core uses less power, saving your battery. Also, since the cores would be running these separate tasks concurrently rather than sequentially, apps could finish tasks faster.

    So this doesn't mean you have a 2Ghz core, but rather two 1Ghz cores that can work concurrently, rather than sequentially. I'm not sure if I've explained the difference clearly, but it is an important distinction to make.

    If you want to read the entire White Paper where NVIDIA explains the benefits of dual core, google "The Benefits of Multiple CPU Cores in Mobile Devices - NVIDIA"
    wes008 likes this.
    02-28-2011 03:05 PM
  3. wes008's Avatar
    Wow, lategordon. Very good explanation! So I guess instead of stacking every task on one processor, it has two cores to assign jobs to. So it couldn't run an application that flat out requires a 2Ghz core, but the app could be designed to have certain tasks put on certain cores.
    02-28-2011 03:42 PM

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