Intel Pentium D 820 (2.8 GHz)
The Pentium D 820 was officially released on May 26, 2005. This engineering sample dates back to Dec 20, 2004 which makes it an early sample. 2004 was about single-core Pentium 4's (still) at 3GHz+ and Athlon's in the 3500+ ballpark.
I tested this sample for a short amount of time and haven't ran into any issues. Even the heat dissipation isn't that bad compared to the early Pentium 4 'Prescott'.