LAME MP3 encoding
We used LAME 3.92 to encode a 101MB 16-bit, 44KHz audio file into a very high-quality MP3. The exact command-line options we used were:

lame --alt-preset extreme file.wav file.mp3

Unfortunately, LAME isn't multithreaded, so Hyper-Threading probably won't help.

The Pentium 4's traditional strength in media encoding tasks continues here. You can see how clock speeds matter more than anything else on the Pentium 4 chips. The Athlon XP, which has only received modest clock speed boosts in the past nine months, doesn't grow much faster as model numbers ramp up.

DivX video encoding

Video encoding tasks are especially well accelerated by the Pentium 4. The DivX encoder loves the P4's SSE2 instructions, and Hyper-Threading is a big gain here, too. Of course, memory bandwidth plays a big role, as well. As a result, the Athlon XP 3200+ needs 66 seconds more in order to encode the same video clip as the Pentium 4 3.2GHz.

Speech recognition
Sphinx is a high-quality speech recognition routine that needs the latest computer hardware to run at speeds close to real-time processing. We use two different versions, built with two different compilers, in an attempt to ensure we're getting the best possible performance.

There are two goals with Sphinx. The first is to run it faster than real time, so real-time speech recognition is possible. The second, more ambitious goal is to run it at about 0.8 times real time, where additional CPU overhead is available for other sorts of processing, enabling Sphinx-driven real-time applications.

Obviously, the new Pentium 4 chips are all very well suited for Sphinx speech recognition. The Athlon XP 3200+ can't even touch the Pentium 4 "C" 2.4GHz.