VirtualDub Audio Extraction
We ripped the audio of at 44 100Hz, no compression using VirtualDub 1.5.8 (Build 18068). Times are in seconds, and lower is better.

Lower times are better
Not much of a difference between the two setups, but the nForce 2 setup does hold a slight one second lead at the same clock speed as the KT600 board.
TMPGEnc 2.521
We used the same Animatrix file and the WAV created from VirtualDub to encode the AVI file to MPEG-2 (a somewhat realistic chore as DVDs are MPEG-2). For the AVI to MPEG-2, we used a bitrate of 5000k/Sec, as this is the midrange for a DVD, which is typically between 1000k/Sec to 10,000k/Sec. Frame size was set to 720x480 (DVD Std) and 16:9 NTSC. Note that lower scores are better.

Lower times are better
Another close battle, but in the end, the nForce 2 proves to be a slightly quicker platform, beating the KT600 by 9 seconds.
Unreal Tournament 2003: Antalus, Min Detail @ 640

Quake 3: Arena, Min Detail @ 640

Although the KX600S Pro is no slouch for gaming, its performance is no match for the nForce 2. The gap in Unreal Tournament 2003 was fairly wide, but the Quake 3 gap was even wider.