Socket 423 is a CPU socket used for early Intel Pentium 4 CPU’s, operating at up to 2GHz. Socket 423, also known as PGA423, is a pin grid array (PGA) socket with 423 pins arranged in a 39×39 matrix with 26×26 pins removed from near the center. Each Socket 423 is 2.1″ x 2.1″ (5.33cm x 5.33 cm).

The Socket 423 was used by Intel for less than a year, from November 2000 to August of 2001.  Socket 423 only supported Pentium 4’s built with the Williamette core.  The fastest CPU supported by Socket 423 is 2.0 Ghz.

Socket 423 was replaced by the Socket 478.
Socket 423

Socket-423 Specifications

For full specifications on Socket-423, refer to 423 Pin Socket (PGA423) Design Guidelines.