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hyper-threading

2010-09-23
2012-12-08
  • David Kleiner
    David Kleiner
    2010-09-24

    JpegView intentionally only uses the physical cores to accelerate image processing. The Atom processor only has one physical core thus only one is used. Using the logical (hyperthreading) cores would not speed up processing, or even slow down it a bit due to synchronization needed.

    Greetings
    David

     
  • Oleg Surfer
    Oleg Surfer
    2010-09-24

    Ok, thanks for reply. :)
    What do you think about SSE 3/4 ? It can speedup viewing ?

     
  • David Kleiner
    David Kleiner
    2010-09-24

    I don't think that this would speed up viewing because the limiting factors are:
    - Jpeg decoding done by the Intel Jpeg library. Here I have no influence on the speed. Latest versions of this lib are somewhat faster on multicore processors but they are commercial and cannot be used in an open source program.
    - SIMD register width. This is 128 bit with SS2 and SSE 3/4. Even AVX will not make this wider for integer data, so no point of using it.
    - Memory bandwidth. Processing involves quite a lot of copying and is therefore also memory limited.