LGA stands for Land Grid Array and is the connection point for a central processing unit (CPU) to fit into a motherboard.
An LGA socket is the connection point for a central processing unit (CPU) to fit into a motherboard. The LGA stands for Land Grid Array, and for Intel CPUs, is usually followed by a number that indicates how many pins are in the socket. When a CPU is inserted into the socket, the pins on the bottom of the socket line up with the holes that cover electrical contacts on the CPU and an electrical (and data bus) connection is made.
Specifications for Compatibility
In addition to specifying which CPUs will work with which motherboards, the LGA specification is also an indicator for how large the physical socket is on the motherboard and how much space is required to mount a cooling device over the CPU. Modern CPUs need extensive cooling to remove waste heat. Failure to do so can cause system instability or cause the CPU to fail catastrophically. CPU coolers will specify which LGA socket size(s) they work with; many can be configured to work with sockets of different sizes.
Benefits of LGA Sockets
LGA sockets reduce the manufacturing costs of making ready-to-insert CPUs; by putting the pins on the motherboard socket, the step can be eliminated when running CPUs through quality control testing. There is an ancillary consumer benefit: if a pin breaks when inserting a CPU, it's usually less expensive to replace a motherboard than it is to replace a CPU. LGA sockets also allow more electrical contact points, which allows for a more stable voltage input for the CPU. However, the general tolerances for computer equipment are robust enough that that any increases in reliability are hard to measure.
Generations of LGA Sockets
The first LGA sockets were used in the mid 1990s for server processors. They became an Intel standard (and a contrast with the older Pin Grid Array sockets used by AMD) in 2004, with the introduction of the LGA 775 socket with the Pentium IV, which was called Socket T. It was quickly followed by the Xeon LGA socket, the LGA 771, and marketed as the Socket J. The LGA 775/771 sockets were replaced with LGA 1366 sockets for high end systems, and with the LGA 1156 socket for the i3, i5 and i7 CPUs for lower end systems. The LGA 1156 socket integrates additional memory controller circuitry into the socket itself as a cost saving measure.
Current Usage
Intel has begun to transition from the LGA 1156 socket to its successor, making the LGA 1156 one of the shortest lived CPU sockets in Intel history. As of January 2011, Intel has announced the LGA 2011 for motherboards coming out in the third quarter of 2011. Unlike Intel, which has made a complete transition to LGA interfaces, AMD releases only a handful of their CPUs in this configuration. The rest in the traditional Pin Grid Array (PGA) format, where pins descend from the CPU.
Tags: Grid Array, 1156 socket, work with, central processing, central processing unit, connection point