The Pentium 4 Extreme Edition (P4EE) announced in September 2003, was aimed at gamers, nicknaming it the "Emergency Edition". This was like Pentium 4 i.e., it would run in the same motherboards, but the difference was an addition of a 2 MB of Level 3 cache. It was twice as fast as that of the Xeon MP in a socket 478 form factor with an 800MHz bus.
A minimal increase in the performance in late 2004 was observed when the bus speed was increased from 800MHz to 1066MHz. The features of the new 3.73GHz Extreme Edition was similar to that of a 6x0-sequence Prescott, but with a 1066MHz bus. However performance wise, the 3.73GHz Extreme Edition was mostly found to be slower than the 3.46GHz version.
