Neoseeker posted their Pentium D 820 Dual Core Review, and AMD X2 4200+ review

In this simulated usage scenario, I began a single-threaded MPEG2 encode along with the usual LAME MP3 encode. Both benchmarks were started at as identical times as I could manage (less than a second of delay between the
start of both).

The results here are surprising. The Pentium D 820 is basically on-par with the X2 4200+. While it loses in TMPGEnc MPEG2 encoding, it wins in LAME MP3 encoding. The Pentium 4 670 at 2.8 GHz takes quite a hit while having to manage both of these tasks at once, though the biggest loser here is the Venice at 2.2 GHz, which gets completely trounced.

Pentium D 820 Dual Core Review, and AMD X2 4200+ Review