What Is Socket 1156?

Socket 1156, better known as LGA 1156, is a central processing unit (CPU) socket that semiconductor company Intel Corporation designed for its Lynnfield- and Clarkdale-codenamed processors. Released in 2009, it is best known as a socket for the i3, i5 and i7 processors, which represented the company’s base, mid-range and top-level entries, respectively, of its flagship Core brand of consumer-oriented CPUs. Besides LGA 1156, Socket 1156 is also known as Socket H.

Like other CPU sockets, Socket 1156 is designed for connecting the processor with the motherboard for electrical conductivity, as well as for physical security and protection. The LGA prefix stands for "land grid array," which is a socket form factor that involves the pins, which accommodate the CPU, arranged in an orderly, four-row, grid-like layout on a square-shaped substrate, with the number 1156 indicting the number of pins. Socket 1156 has an LGA variant called flip-chip LGA (FCLGA). This means that the CPU is flipped over to expose its back, which is its hottest part. Thus, a user can place a heatsink there to dissipate heat and consequently reduce the possibility of CPU malfunction.

The physical dimensions of Socket 1156 is about 1.57 square inches (40 square millimeters), made to accommodate the 1.48-square inch (37.5-square mm) compatible chips. A 0.94-by-0.63-inch (24-by-16-mm) section is cut off at the middle. The pin pitch size is 0.036 inches (0.9144 mm).

Socket 1156 supports the dual-core i3-5xx series of the Core i3, dual-core i5-6xx and quad-core i5-7xx series of the Core i5, and quad-core i7-8xx series of the Core i7. The LGA 1155-compatible Core i3 has a 2.93-to-3.2-gigahertz (GHz) processing speed range. The ranges of the i5-6xx and -7xx series are 3.2 to 3.6 GHz and 2.66 to 2.8 GHz, respectively; while that of the i7 is 2.8 to 2.93 GHz. Regarding memory specifications, all Socket 1156-compatible Intel Core chips support two channels of third-generational double data rate synchronous dynamic random access memory (DDR3 SDRAM) architecture with a maximum 1,333-MHz speed.

The Intel Core is not the only CPU brand that Socket 1156 supports. There is also the dual-core G1xxx series of the low-end Celeron and G6xxx series of the mid-range Pentium, as well as the quad-core L34xx and X34xx series of the server- and workstation-oriented Xeon. The processing speeds are 2.26 GHz, 2.8 GHz, 1.86 GHz and 2.4 to 2.93 GHz, respectively. While the Socket 1156-compatible Xeon uses the same maximum 1,333-MHz DDR3 SDRAM standard of the Core chips, the Celeron and Pentium’s peak memory speed is lower, at 1,066 MHz.