Media encoding and editing

x264 HD benchmark
This benchmark tests performance with 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. These scores come from the newer, faster version 0.59.819 of the x264 executable.

We've chosen to report results for the individual passes, then report an aggregate result based on a sum of encoding times for both passes. We'll be basing our value calculations on that aggregate.

Multiple cores shine in recent video encoding applications like this, so it's no surprise to see the Phenom II X3 720 being (apparently) penalized for its lack of a fourth core. Like in The Panorama Factory, the Core 2 Quad Q8200 is one of the most attractive deals here in spite of its low clock speed.

Windows Media Encoder x64 Edition video encoding
Windows Media Encoder is one of the few popular video encoding tools that uses four threads to take advantage of quad-core systems, and it comes in a 64-bit version. Unfortunately, it doesn't appear to use more than four threads, even on an eight-core system. For this test, we asked Windows Media Encoder to transcode a 153MB 1080-line widescreen video into a 720-line WMV using its built-in DVD/Hardware profile. Because the default "High definition quality audio" codec threw some errors in Windows Vista, we instead used the "Multichannel audio" codec. Both audio codecs have a variable bitrate peak of 192Kbps.

Windows Media Encoder delivers results similar to those of the x264 HD benchmark, although the AMD processors perform relatively better. The Core 2 Quad Q8200 and Phenom II X4 810 are practically neck-and-neck on the value scale here, the latter being both faster and more expensive.

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. You can download a paper (in Word format) describing the programming effort.

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 are encoding a massive 10-minute, 6-second 101MB WAV file. Our results are from a 64-bit version of LAME MT built using an Intel compiler. We left out results from the build made with a Microsoft compiler since this version produces lower encoding times with both Intel and AMD processors (and it apparently doesn't penalize the AMD CPUs).

Surprise, surprise: the Core 2 Duo E8400 looks extremely well-positioned in a benchmark that doesn't benefit from more than two cores.