LGA 775 (land grid array 775), also known as Socket T, is an Intel desktop CPU socket. Unlike earlier common CPU sockets, such as its predecessor Socket 478, the LGA 775 has no socket holes; instead, it has 775 protruding pins which touch contact points on the underside of the processor (CPU).
The socket had an unusually long life span, lasting 7 years until the last processors supporting it ceased production in 2011.
The socket was superseded by the LGA 1156 (Socket H) and LGA 1366 (Socket B) sockets.
- Pentium 4
- Pentium 4 HT
- Pentium 4 HT Extreme Edition
- Pentium D
- Celeron / Celeron D
- Pentium Dual Core
- Pentium Extreme Edition
Heatsink design: For LGA 775, the distance between the screw-holes for the heat sink is 72 mm. Such heat-sinks are not interchangeable with heat sinks for sockets that have a distance of 75 mm, such as LGA 1156, 1155, 1150, 1151.
LGA 1156 (land grid array 1156), also known as Socket H or H1, is an Intel desktop CPU socket. Its incompatible successor is LGA 1155.
The last processors supporting it ceased production in 2011.
LGA 1156, along with LGA 1366, were designed to replace LGA 775. Whereas LGA 775 processors connect to a north bridge using the Front Side Bus, LGA 1156 processors integrate the features traditionally located on a north bridge within the processor itself. The LGA 1156 socket allows the following connections to be made from the processor to the rest of the system:
- PCI-Express 2.0 ×16 for communication with a graphics card. Some processors allow this connection to be divided into two ×8 lanes to connect two graphics cards. Some motherboard manufacturers use NVIDIA’s NF200 chip to allow even more graphics cards to be used.
- DMI for communication with the Platform Controller Hub (PCH). This consists of a PCI-Express 2.0 ×4 connection.
- FDI for communication with the PCH. This consists of two Display Port connections.
- Two memory channels for communication with DDR3 SDRAM. The clock speed of the memory that is supported will depend on the processor.
The LGA 1156 and LGA 1366 sockets and processors were discontinued sometime in 2012, having been superseded by the LGA 1155 and LGA 2011 respectively.
Heatsink: For LGA 1156 the 4 holes for fastening the heat sink to the motherboard are placed in a square with a lateral length of 75 mm. This configuration was retained for the later, LGA 1155, LGA 1150, and LGA 1151 sockets meaning that cooling solutions should generally be interchangeable.
LGA 1366 (land grid array 1366), also known as Socket B, is an Intel CPU socket. This socket supersedes Intel’s LGA 775 (Socket T) in the high-end and performance desktop segments. It also replaces the server-oriented LGA 771 (Socket J) in the entry level and is superseded itself by LGA 2011. This socket has 1,366 protruding pins which touch contact points on the underside of the processor (CPU) and accesses up to three channels of DDR3 memory via the processor’s internal memory controller.
In November 2008, Intel released Core i7, which was the first processor requiring this socket.
LGA 1366 socket and processors were discontinued sometime in early 2012, having been superseded by the LGA 2011 socket, on 14 November 2011, supporting Sandy Bridge E-series processors. The accompanying LGA 1156 was discontinued at the same time, which was replaced by LGA 1155.
LGA 1155, also called Socket H2, is a socket used for Intel microprocessors based on Sandy Bridge (2nd-Gen, 32nm, 2k-series) and Ivy Bridge (3rd-Gen, 22nm, 3k-series) micro architectures.
It is the successor of LGA 1156 (known as Socket H) and was itself succeeded by LGA 1150 in 2013. Along with selected variations of LGA 2011 socket, it was the last Intel socket to fully support Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008.
LGA 1155 has 1155 protruding pins to make contact with the pads on the processor. The pins are arranged in a 40×40 array with a 24×16 central void and additional 61 omitted pins (two adjoining the central void, six in each of the four corners, and 35 in groups around the perimeter), yielding the 1600 − 384 − 61 = 1155 pin count. Processors for LGA 1155 and LGA 1156 sockets are not compatible with each other since they have different socket notches.
LGA 1155 also marked the beginning of secure boot with support in some later boards.
Heatsink: The 4 holes for fastening the heat sink to the motherboard are placed in a square with a lateral length of 75 mm for Intel’s sockets LGA 1156, LGA 1155, LGA 1150, LGA 1151 and LGA 1200. Cooling solutions should therefore be interchangeable. Cooling systems are compatible between LGA 1155 and LGA 1156 sockets, as the processors have the same dimensions, profile and construction, and similar levels of heat production.