Socket 423 is a 423-pin CPU socket used by Intel's first generation of Pentium 4 processors based on the Willamette core.
This socket was short-lived, as it became apparent that its electrical design proved inadequate for raising clock speeds beyond 2.0 GHz. Intel produced chips using this socket for less than a year, from November 2000 to August 2001.
Socket 423 was replaced by Socket 478 in 2001. Socket 478, being microPGA, was cheaper to manufacture than Socket 423.[1]
Socket 423 was designed to house any processor in the Socket 423 package.
All processors using this socket have a locked multiplier, meaning that they are not overclockable unless the front side bus frequency is increased. Doing this, however could push other buses out of spec, causing erratic behaviors such as system instability and premature failure.
The "PowerLeap PL-P4/N" is a device developed in the form of a socket adapter that allows the use of Socket 478 processors in Socket 423 motherboards.