Rare Intel Pentium 4 engineering sample with 4 GHz clock speed surfaces

A rare Intel Pentium 4 engineering sample with a 4 GHz clock speed has surfaced online. This processor's existence was previously unknown. The chip, identified as a Pentium Extreme Edition 980, was shared on Reddit with photos and CPU-Z information. It is believed to be a pre-production unit loaned to an Intel employee. This specific model never reached mass production due to thermal and power efficiency issues, as Intel shifted focus to the Core 2 architecture.