Socket 478

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title: "Socket 478" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["intel-cpu-sockets"] description: "Processor socket made by Intel" topic_path: "general/intel-cpu-sockets" source: "https://en.wikipedia.org/wiki/Socket_478" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Processor socket made by Intel ::

name = Socket 478 | image = [[File:Socket PGA478B.jpg|300px]] | formfactors = Flip-chip pin grid array (FC-PGA2 or FC-PGA4) | contacts = 478 (not to be confused with the newer Socket P or the similar Socket 479)| type = PGA-ZIF | protocol = AGTL+ | fsb = 400 MT/s 533 MT/s 800 MT/s | voltage =1.25 V - 1.525 V | dimensions = 35 mm × 35 mm | processors = Pentium 4 (1.4–3.4 GHz) Celeron (1.7–2.8 GHz) Celeron D (2.13–3.2 GHz) Pentium 4 Extreme Edition (3.2–3.4 GHz) | predecessor = Socket 423 | successor = LGA 775 |release-date=2001|designed-by=Intel}}

::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/fc/Pentium_4_-SL5TK-_pin_side-3057.jpg" caption="Willamette]] with Socket 478 (2001), pin side"] ::

Socket 478, also known as mPGA478 or mPGA478B, is a 478-contact CPU socket used for Intel's Pentium 4 and Celeron series CPUs.

Socket 478 was launched in August 2001 in advance of the Northwood core to compete with AMD's 462-pin Socket A and their Athlon XP processors. Socket 478 was intended to be the replacement for Socket 423, a Willamette-based processor socket which was on the market for only a short time.

This was the last Intel desktop socket to use a pin grid array (PGA) interface. All later Intel desktop sockets use a land grid array (LGA) interface.

Socket 478 was phased out with the launch of LGA 775 in 2004.

Technical specifications

Socket 478 was used for all Northwood Pentium 4 and Celeron processors. It supported the first Prescott Pentium 4 processors and all Willamette Celerons, along with several of the Willamette-series Pentium 4s. Socket 478 also supported the newer Prescott-based Celeron D processors (which were also one of the last CPUs made for the socket), and early Pentium 4 Extreme Edition processors with 2 MB of L3 CPU cache.

While Intel's mobile CPUs are available in 478-pin packages, they in fact only operate in a range of slightly differing sockets such as Socket 479, Socket M, and Socket P, all of which are electrically incompatible with each other including Socket 478.

Socket 478 is used in combination with DDR SDRAM, as well as SDR SDRAM, RDRAM and DDR2 SDRAM.

Heatsink

The 4 holes for fastening the heatsink to the motherboard are placed in a rectangle with lateral lengths of 60 mm and 75 mm.

Mechanical load limits

All sockets (Pentium 4 and Celeron) have the following mechanical maximum load limits which should not be exceeded during heatsink assembly, shipping conditions, or standard use. Load above those limits may crack the processor die and make it unusable. The limits are included in the table below. ::data[format=table]

Location	Dynamic	Static	Transient
IHS Surface	890 N (200 lbf)	445 N (100 lbf)	667 N (150 lbf)
::

Chipsets

Intel

References

References

1. (April 09, 2006). "Intel Pentium 4 Datasheet".
2. "Socket 479 / Socket mPGA479M".

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::