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Media encoding and editing

x264 HD benchmark
This benchmark tests one of the most popular H.264 video encoders, the open-source x264. The results come in two parts, for the two passes the encoder makes through the video file. I've chosen to report them separately, since that's typically how the results are reported in the public database of results for this benchmark

If you're into encoding video, you've no doubt come to appreciate the benefits of a fast multi-core processor. The Athlon II X4 635 finishes pass two of this process in about half the time that the Athlon II X2 255 or Pentium E6500 does, for example. Video encoding has been an optimization target for CPU architects for some time now, and we've seen marked progress, obviously, as the Pentium 4 670's relatively abysmal frame rates illustrate.

Windows Live Movie Maker 14 video encoding
For this test, I used Windows Live Movie Maker to transcode a 30-minute TV show, recorded in 720p .wtv format on my Windows 7 Media Center system, into a 320x240 WMV-format video format appropriate for mobile devices.

Since these results are measured in seconds, they illustrate my point even better. If you pick an Athlon II X4 635 instead of a Core i3-530 for your system, you can expect an encode process like this one to finish about 30 seconds sooner. The justification for a high-end processor is pretty clear: you'll save over four and a half minutes by going with a Core i7-960 instead of a Pentium E6500. If time is money, fast computer hardware may seem rather cheap in the big picture.

LAME MT audio encoding
LAME MT is a multithreaded version of the LAME MP3 encoder. LAME MT was created as a demonstration of the benefits of multithreading specifically on a Hyper-Threaded CPU like the Pentium 4. Of course, multithreading works even better on multi-core processors.

Rather than run multiple parallel threads, LAME MT runs the MP3 encoder's psycho-acoustic analysis function on a separate thread from the rest of the encoder using simple linear pipelining. That is, the psycho-acoustic analysis happens one frame ahead of everything else, and its results are buffered for later use by the second thread. That means this test won't really use more than two CPU cores.

We have results for two different 64-bit versions of LAME MT from different compilers, one from Microsoft and one from Intel, doing two different types of encoding, variable bit rate and constant bit rate. We are encoding a massive 10-minute, 6-second 101MB WAV file here.

Audio encoding is one of those areas where multithreading will only take you so far. Unless you're batching up multiple songs and encoding them together at once, you probably won't benefit much from having more than two cores.