Socket 478

By :http://en.wikipedia.org/wiki/Socket_478

Socket 478
Specifications
Type :PGA-ZIF

Chip form factors:Flip-chip pin grid array (FC-PGA2 or FC-PGA4)

Contacts:478

Bus Protocol:AGTL+

FSB:400 MT/s533 MT/s800 MT/s

Voltage range


Processors :
Intel Pentium 4 (1.4 - 3.4 GHz)Intel Celeron (1.7 - 2.8 GHz)Celeron D (2.13 - 3.2 GHz)Intel Pentium 4 Extreme Edition (3.2, 3.4 GHz)

In computing, Socket 478 is a type of CPU socket used for Intel's Pentium 4 and Celeron series CPUs. Socket 478 was phased out with the launch of LGA775.
Socket 478 has been used for all of the Northwood Pentium 4s and Celerons, the first Prescott Pentium 4s, and some Willamette Celerons and Pentium 4s. Socket 478 also supports newer Prescott Celeron Ds, and early Pentium 4 Extreme Edition processors with 2MB of L3 cache and some Core Duos. The socket was launched with the Northwood core to compete with AMD's 462-pin Socket A and their Athlon XP processors. Socket 478, which accommodates high and low-end processors, was also the replacement for Socket 423, a Willamette processor socket which remained in the market for only a short time.
Motherboards that use this socket support DDR, RDRAM, and in some cases SDRAM. However, the majority of boards are DDR based. Initial motherboards only supported RDRAM, however RDRAM is quite expensive, compared to DDR and SDRAM, and consumers demanded an alternative, thus DDR and SDRAM boards were made. Later revisions to chipsets that support Socket 478 added higher FSB speeds, higher DDR speeds, and support for dual channel DDR.
Like the previous Socket 423, Socket 478 is based on Intel's Quad Data Rate technology, with data transferring at four times the clock rate of its Front Side Bus. As such, the 400 MT/s bus was based on a 100 MHz clock signal, but was still able to provide 3.2GB/s of data to the chipset. At its release, no SDRAM product was capable of supporting so high a data rate, so Intel pushed forward RDRAM technology, with two channels of PC800 providing synchronous data capability. Poor consumer acceptance of expensive RDRAM lead Intel to release low-performance PC133-supporting chipsets, and finally DDR chipsets.
While the original 400 MT/s bus matched the data rate of PC3200, this bus speed was already outdated by the time PC3200 became available. Dual-channel memory was introduced on later chipsets, so that a matched pair of PC3200 modules was able to match the final 800 MT/s FSB.
The Celeron D is also available for Socket 478 and they are now the only CPU's still made for the socket. They use a quad-pumped 133MHz Bus Giving A 533MT/s FSB. They are available with 256KB L2 Cache and are built on the 90nm manufacturing process, using the Prescott Core.
Socket 478 is officially known by Intel as FC-PGA2 [1]. While Core Duo is available in a 478-pin package, that socket is different: micro FC-PGA [2], which was also used for earlier Pentium M and Celeron M processors. Core Duo is also available in a 479-ball (not pin) package known as micro FC-BGA.
Socket 478 mechanical load limits
All socket 478 processors(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 will crack the processor die and make it unusable.

LocationDynamicStaticTransientIHS Surface

890 N(200 lbf)
445 N(100 lbf)
667 N(150 lbf)