Slow HandBrake conversion on 2011 i7?

Discussion in 'iMac' started by 88 King, Jul 5, 2011.

  1. 88 King, Jul 5, 2011
    Last edited: Jul 5, 2011

    88 King macrumors 6502

    88 King

    Jun 18, 2011
    London, UK
    I'm currently converting some films to ipad format using HandBrake. The CPU is going full speed according to Active monitor at 720%, and istat menu is reporting 97% usage with all 8 threads.

    However, I'm only getting average 60 fps in handBrake. With my old i7 960 (3.2GHz) Windows 7 PC, I'm used to getting 80 to 100 fps at only 30% CPU usage. In fact I use to open 3 separate HandBrake conversions at the same time with higher fps than I'm getting now on the imac. :confused:

    I don't have Bootcamp installed at the moment so can't test HandBrake in Windows. Does everybody else also getting the same fps or are your's is much higher?


    Edit: I'm mainly converting from 720p films around 8 to 10 Gb.
  2. gmanist1000 macrumors 68030


    Sep 22, 2009
    I have the 3.4GHz i7 Model. Mine fluctuated between 80-150FPS, but occasionally it was below 80, and sometimes down to 60.
  3. Nanker/Phelge macrumors regular

    Dec 6, 2010
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_3 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5)

    It will depend on what you're encoding and what preset you're using.

    I can tell you that my 2.93 Nehalem i7 does 40 FPS from a Blu-ray MKV to an "Apple TV 2" preset...
  4. thebignewt macrumors regular

    Jun 10, 2011
  5. aliensporebomb macrumors 68000


    Jun 19, 2005
    Minneapolis, MN, USA, Urth

    -How much memory do you have installed?
    -What does your machine geekbench? and run the app.

  6. 88 King thread starter macrumors 6502

    88 King

    Jun 18, 2011
    London, UK
    The video files does not have copyright protection, they all are ripped from DVDs.

    This imac with i7 @ 3.4 GHz and 8Gb of RAM gives geekbench score of 11300.

    My old Windows 7 PC with i7 960 @ 3.2 GHz and 6Gb of RAM @ 1600MHz gives geekbench score around 8500. With the CPU overclocked to 4.2 GHz and RAM @ 1400MHz, geekbench score was about same as my current imac.

    I'm going to swap the stock HD with a SSD today and install Bootcamp, first thing I'll do is to test HandBrake under Windows 7.

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