Articles in the Hardware category

  1. FFmpeg Performance on a Core I7 920 @ 3.6 Ghz

    Wed 22 April 2009

    The system i'm running is a Core i7 920 @ 3.6 Ghz.

    I am transcoding a DVD (Grave Of The Fire Flies) to iPod format (640x480 x264).

    Thread support is enabled, to FFmpeg uses about 250% CPU. That's 2.5 of the 4 cores available. If possible, I would have liked to see it use all four to the max.

    Any way. I use these settings:

    FFmpeg version SVN-r18628

    ffmpeg -i $1 -pass 1 -acodec libfaac -ab 128k -ac 2 -vcodec libx264 -vpre normal -vpre ipod640 -s 640x480 -b 512k -bt 512k -threads 0 -f mp4 $2

    With these settings, I get an encoding speed of fps=193.

    I don't know how that stacks up against other systems. It seems fast to me though. In effect, the system is playing the DVD at 7.6 times the speed of the movie (25 fps?). So encoding is 88 minutes / 7.6 = 11.45 minutes for encoding a DVD to iPod x264.

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  2. Core I7 920 @ 3,6 Ghz Is a True Beast!

    Wed 04 March 2009

    Even today, Core 2 Duo processors clocked at 2 ghz are no slugs. However, the Core i7 920 is of a different kind. First, it is not only clocked at a higher speed (default 2,8 Ghz), it is also a quad-core processor. Thanks to the re- introduction of hyperthreading, this processor can handle 8 parallel proceses simultaneously.

    Just how fast a Core i7 can be, especially if overclocked to 3,6 Ghz shows this diagram:

    chart

    Using my still in development version of PPSS, four systems processed 400 GB of WAV files and converted them to MP3. This simple pie-chart shows that the Core i7 on it's own, using 8 parallel processes, managed to process 2/3 of the files. The Core i7 was way faster than the other 3 systems combined! This is marvelous, I think. And it seems all due to Hyperthreading. If an additional duo core system would have been added, the other systems combined would have also 8 parallel threads available and would have processed roughly 50% of the items. However, please note that the Core i7 is a quad core processor and has 'only' four physical cores...

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