Parallelization Efficiency: Estimating multi-core CPU performance using Amdahl's Law

By Jos
May 14, 2015
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  1. estimating cpu performance amdahl law

    When you are choosing a CPU, there are two main specifications you need to pay attention to that define the relative performance of two CPUs based on the same architecture: frequency and number of cores. While hardware review sites like TechSpot do a great job testing and comparing different CPUs, unless they specifically benchmark the applications you personally use their results may not accurately reflect the performance that you would see.

    If your software only uses a single core, the frequency is a decent indicator of how well a CPU will perform. However, if your software is able to utilize multiple CPU cores it becomes very difficult to estimate the performance of different CPU models since almost no program is going to be 100% efficient at using those cores. The trick is to determine exactly how efficient your program is at using multiple CPU cores (it's parallelization efficiency) and use that number to estimate the performance of different CPU models.

    To calculate the parallelization efficiency, you need to use a mathematical equation called Amdahl's Law. Don't worry, though, we'll give you the theory but for those that don't particularly love math there's an "Easy Mode" spreadsheet.

    Read the complete article.

  2. VitalyT

    VitalyT Russ-Puss Posts: 3,114   +1,377

    then the rest of the article is a complete overkill.

    It is educationally interesting, just with the wrong preamble.
    madboyv1, Cryio and wastedkill like this.
  3. MoeJoe

    MoeJoe TS Maniac Posts: 363   +174

    Wow. Really ?
  4. MoeJoe

    MoeJoe TS Maniac Posts: 363   +174

    So many tech sites try to provide useful info.
    So many more regurgitate the same, shallow marketing spin - trying to be unique & relevant.
    Very few dig in and get dirty whilst producing some useful and READABLE content to many.
    This article is that.
    This article is a great tutorial on not only critical thinking, but how it relates to what
    we usually buy vs. what we REALLY need ... most of the time.

    I applaud TechSpot and specifically, Matt, for this great article !
    Last edited: May 14, 2015
  5. Puiu

    Puiu TS Evangelist Posts: 1,813   +484

    This is why kids, smart people learn math and not so smart people learn how to make money! ^_^
  6. Joao Ribeiro

    Joao Ribeiro TS Rookie

    "The frequency is how many operations a single CPU core can complete in a second (how fast it is)." WRONG

    The frequency reflects the speed at witch the CPU is clocked, the number of instructions a CPU performs is measured per clock tick (per hertz) and is named IPC. To get a usable performance number you multiply the IPC and the clock frequency to get at it's value. I'm not even reading another line of this fallacious article.

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