A CPU socket or CPU slot is a connector on a computer's motherboard that accepts a CPU and forms an electrical interface with it. As of 2007, most desktop and server computers, particularly those based on the Intel x86 architecture, include socketed processors.
Most CPU-sockets interfaces are based on the pin grid array (PGA) architecture, in which short, stiff pins on the underside of the processor package mate with holes in the socket. To minimize the risk of bent pins, zero insertion force (ZIF) sockets allow the processor to be inserted without any resistance, then grip the pins firmly to ensure a reliable contact after a lever is flipped.
As of 2007, several current and upcoming socket designs use land grid array (LGA) technology instead. In this design, it is the socket which contains pins. The pins contact pads or lands on the bottom of the processor package.
In the late 1990s, many x86 processors fit into slots, rather than sockets. CPU slots are single-edged connectors similar to expansion slots, into which a PCB holding a processor is inserted. Slotted CPU packages offered two advantages: L2 cache memory could be upgraded by installing an additional chip onto the processor PCB, and processor insertion and removal was often easier. However, slotted packages require longer traces between the CPU and chipset, and therefore became unsuitable as clock speeds passed 500 MHz. Slots were abandoned with the introduction of AMD's Socket A and Intel's Socket 370.
Most CPU-sockets interfaces are based on the pin grid array (PGA) architecture, in which short, stiff pins on the underside of the processor package mate with holes in the socket. To minimize the risk of bent pins, zero insertion force (ZIF) sockets allow the processor to be inserted without any resistance, then grip the pins firmly to ensure a reliable contact after a lever is flipped.
As of 2007, several current and upcoming socket designs use land grid array (LGA) technology instead. In this design, it is the socket which contains pins. The pins contact pads or lands on the bottom of the processor package.
In the late 1990s, many x86 processors fit into slots, rather than sockets. CPU slots are single-edged connectors similar to expansion slots, into which a PCB holding a processor is inserted. Slotted CPU packages offered two advantages: L2 cache memory could be upgraded by installing an additional chip onto the processor PCB, and processor insertion and removal was often easier. However, slotted packages require longer traces between the CPU and chipset, and therefore became unsuitable as clock speeds passed 500 MHz. Slots were abandoned with the introduction of AMD's Socket A and Intel's Socket 370.
CPU Package Type
PGA(pin grid array)
FC-PGA Package TypeThe FC-PGA package is short for flip chip pin grid array, which have pins that are inserted into a socket. These chips are turned upside down so that the die or the part of the processor that makes up the computer chip is exposed on the top of the processor. By having the die exposed allows the thermal solution can be applied directly to the die, which allows for more efficient cooling of the chip. To enhance the performance of the package by decoupling the power and ground signals, FC-PGA processors have discrete capacitors and resistors on the bottom of the processor, in the capacitor placement area (center of processor). The pins on the bottom of the chip are staggered. In addition, the pins are arranged in a way that the processor can only be inserted one way into the socket. The FC-PGA package is used in Pentium® III and Intel® Celeron® processors, which use 370 pins.
OOI Package Type
OOI is short for OLGA. OLGA stands for Organic Land Grid Array. The OLGA chips also use a flip chip design, where the processor is attached to the substrate facedown for better signal integrity, more efficient heat removal and lower inductance. The OOI then has an Integrated Heat Spreader (IHS) that helps heatsink dissipation to a properly attached fan heatsink. The OOI is used by the Pentium 4 processor, which has 423 pins.FC-PGA2 Package
TypeFC-PGA2 packages are similar to the FC-PGA package type, except these processors also have an Integrated Heat Sink (IHS). The integrated heat sink is attached directly to the die of the processor during manufacturing. Since the IHS makes a good thermal contact with the die and it offers a larger surface area for better heat dissipation, it can significantly increase thermal conductivity. The FC-PGA2 package is used in Pentium III and Intel Celeron processor (370 pins) and the Pentium 4 processor (478 pins).
FC-LGA4 Package Type
The FC-LGA4 package is used with Pentium® 4 processors designed for the LGA775 socket. FC-LGA4 is short for Flip Chip Land Grid Array 4. FC (Flip Chip) means that the processor die is on top of the substrate on the opposite side from the LAND contacts. LGA (LAND Grid Array) refers to how the processor die is attached to the substrate. The number 4 stands for the revision number of the package.This package consists of a processor core mounted on a substrate land-carrier. An integrated Heat Spreader (IHS) is attached to the package substrate and core and serves as the mating surface for the processor component thermal solution such as a heatsink.You may also see references to processors in the 775-LAND package. This refers to the number of contacts that the new package contains that interface with the LGA775 socket.The pictures below include the LAND Slide Cover (LSC). This black cover protects the processor contacts from damage and contamination and should be retained and placed on the processor whenever it is removed from the LGA775 socket.
S.E.C.C. Package Type
S.E.C.C. is short for Single Edge Contact Cartridge. To connect to the motherboard, the processor is inserted into a slot. Instead of having pins, it uses goldfinger contacts, which the processor uses to carry its signals back and forth. The S.E.C.C. is covered with a metal shell that covers the top of the entire cartridge assembly. The back of the cartridge is a thermal plate that acts as a heatsink. Inside the S.E.C.C., most processors have a printed circuit board called the substrate that links together the processor, the L2 cache and the bus termination circuits. The S.E.C.C. package was used in the Intel Pentium II processors, which have 242 contacts and the Pentium® II Xeon™ and Pentium III Xeon processors, which have 330 contacts.
S.E.P. Package Type
S.E.P. is short for Single Edge Processor. The S.E.P. package is similar to a S.E.C.C. or S.E.C.C.2 package but it has no covering. In addition, the substrate (circuit board) is visible from the bottom side. The S.E.P. package was used by early Intel Celeron processors, which have 242 contacts.
S.E.C.C.2 Package Type
The S.E.C.C.2 package is similar to the S.E.C.C. package except the S.E.C.C.2 uses less casing and does not include the thermal plate. The S.E.C.C.2 package was used in some later versions of the Pentium II processor and Pentium III processor (242 contacts).
