Micro Processors, and Socket Types

Micro processor, also called CPU (Central Processing Unit), is a major component of a micro computer. We discuss various CPUs starting from Pentium IV, and onwards. 

• Socket 478 
• Socket 423 
• Socket 370 
• Socket 8 
• Socket 7 
• Socket A 
• Slot A 
• Slot 2 
• Slot 1  

Socket 478 :- Socket 478 is a PGA socket used by Intel Pentium 4 microprocessor family (not all P IV family processors support Socket 478)..

• Front Bus Frequencies: 400 MHz - 800 MHz (100 MHz - 200 MHz QDR)
• Socket size: 1.38" x 1.38" (3.5 x 3.5 cm)
• Number of contacts: 478
• Compatible package types :- 478-pin micro FC-PGA // 478-pin micro FC-PGA2
• Compatible processors :- Processors Intel Pentium 4 (1.4 - 3.4 GHz) // Intel Celeron (1.7 - 3.2 GHz) // Celeron D (to 3.2 GHz) // Intel Pentium 4 Extreme Edition (3.2, 3.4 GHz)
• This socket has currently been replaced with socket 775.

Socket 423 :- The socket was used for low-end Pentium IV processors below 2000MHz frequencies. It became obsolete with the advent of Socket 478. 

• Number of Contacts: 423
• Compatible package type :- Organic Land Grid Array (OLGA)
• Front Bus Speed :- 100 MHz FSB
• Compatible Processors :- Intel Pentium 4 (1300 MHz - 2000 MHz)

Socket 370 :- Socket 370 (PGA370) is a PGA socket compatible with Intel Celeron and Pentium III processors in Pin Grid Array (PGA) package.

• Compatible package types :- 370-pin Plastic Pin Grid Array (PPGA); 370-pin Flip-Chip Pin Grid Array (FC-PGA) // 370-pin Flip-Chip Pin Grid Array (FC-PGA2)
• Number of contacts: 370
• Front Bus Frequencies:  66, 100 and 133 MHz
• Supported Processors include the following :- Intel Celeron (PPGA, 300–533 MHz) // Intel Celeron (FC-PGA, 533–1100 MHz) // Intel Celeron (FC-PGA2, 900–1400 MHz) // Intel Pentium III (FC-PGA, 500–1133 MHz) // Intel Pentium III Tualatin (FC-PGA2) // Celeron Tualatin (FC-PGA2) // VIA C3 (FC-PGA)

Socket 8 :- Socket 8  was used for a very limited number of processor types. The socket is being no more used by newer processors.

• Number of Contacts :- 387 
• Front Bus Speed :- 66-75 MHz
• Supported Processors include the following :- Pentium Pro 150~200, Pentium II OverDrive 300~333

Socket 7 :- Socket 7 was introduced by Intel for Pentium 133 - 200 MHz processors. It is also used in Pentium MMX processor family. 

• Compatible package types :- 296-pin staggered Plastic Pin Grid Array (PPGA) // 296-pin staggered Ceramic Pin Grid Array (CPGA or SPGA) // 296-pin Flip-Chip staggered Ceramic Pin Grid Array // 321-pin ceramic Ping Grid Array (CPGA)
• Number of contacts :- 321
• Front Bus Frequencies :-  66 - 83 Mhz System Clock
• Supported Processors include the following :- AMD K5 (75 MHz - 200 MHz); AMD K6 (166 MHz - 300 MHz) // AMD K6-2 (200 MHz - 570 MHz) // AMD K6-III (333 MHz - 550 MHz) // Cyrix 6x86, 6x86L and 6x86MX (90 MHz - 266 MHz) // Cyrix MII (233 MHz - 433 MHz) // Intel Pentium (non-MMX) (75 MHz - 200 MHz) // Intel Pentium MMX (166 MHz - 233 MHz)

Socket A (Socket 462) :- Socket A (also called Socket 462) is a PGA socket compatible with AMD K7 family of processors. 

• Bus Frequencies :- 100 MHz, 133 MHz, 166 MHz and 200 MHz
• Number of contact pins: 462 pin holes
• Compatible Processors include the following :- AMD Athlon (650 MHz - 1400 MHz) // AMD Athlon XP (1500+ - 3300+) // AMD Duron (600 MHz - 1800 MHz) // AMD Sempron (2000+ - 3300+) // AMD Athlon MP (1000 MHz - 3000+) 
• Compatible package types :- 462-pin ceramic Pin Grid Array (PGA) package, 462-pin organic PGA.

Slot A :- Slot A is used by AMD's Athlon family of processors. It has 242 contacts, physically similar to that of Intel's Slot 1. But Slot A is electrically different from that of Slot 1.

Slot 1 is a Slot-type connector. This connector is compatible with Pentium II family of processors, and some of low-end Celeron processors. Pentium III was the last microprocessor family that used the Slot 1. 

• Pentium IV family of processors do not use Slot 1. 
• Number of Contacts :- 242
• Processors types supported include the following :- Intel Celeron (SECC, 233-466 MHz) // Processors Intel Pentium II (SECC, 233-450 MHz) // Intel Pentium III (SECC2, 450-1133 MHz)
• Compatible package types :- Single Edge Processor Package (SEPP) // Single Edge Connector Cartridge (SECC) // Single Edge Connector Cartridge 2 (SECC 2)

Slot 2 :- Slot 2 is a 330 contact version of Slot 1. Intel's Xeon processor uses Slot 2. The Slot 2 cartridge may house as many as four processors and an L2 cache.