LGA 1155

LGA 1155, also called Socket H2, is a zero insertion force flip-chip land grid array (LGA) CPU socket designed by Intel for their CPUs based on the Sandy Bridge (second generation core) and Ivy Bridge (third generation) microarchitectures.

LGA 1155

Type	LGA-ZIF
Chip form factors	Flip-chip
Contacts	1155
FSB protocol	PCI Express
Processor dimensions	37.5 × 37.5mm 1,406.25mm2[1]
Processors	Sandy Bridge Ivy Bridge
Predecessor	LGA 1156
Successor	LGA 1150
Memory support	DDR3
This article is part of the CPU socket series

View of the socket LGA 1155 on an Intel Core i7 Sandy Bridge 2600K model CPU

Celeron G530 "Sandy Bridge" installed on a Socket 1155

Introduced in 2011, 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 UEFI secure boot with support in some later boards.

Heatsink

The four holes for fastening the heatsink to the motherboard are placed in a square with a lateral length of 75mm 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.^[2]

Sandy Bridge family of chipsets

See also: Cougar Point and List of Intel chipsets § LGA 1155

Sandy Bridge chipsets, except B65, Q65 and Q67, support both Sandy Bridge and Ivy Bridge CPUs through a BIOS upgrade.^[3] With third-party BIOSes like Coreboot, Ivy Bridge processors can be used on those chipsets as well.^[4] Processors based on Sandy Bridge officially support up to DDR3-1333 memory, however in practice speeds up to DDR3-2133 have been tested to work successfully.^[5]

The H61 chipset only supports one double-sided DIMM Memory module (RAM module) per memory-channel and therefore is limited to 16 GB instead of the 32 GB like the others support.^[6] On H61-based motherboards with four DIMM slots, only four single-sided DIMMs can be installed.^[7]

Name[8]		H61	B65	Q65	Q67	H67[9]	P67	Z68[10]
Overclocking		GPU					CPU + RAM	CPU + GPU + RAM
Allows using built-in GPU with Intel Clear Video Technology		Yes					No	Yes
Maximum USB 2.0 ports[a]		10	12	14
Maximum SATA ports	2.0	4
	3.0	0	1	2
Main PCIe configuration		1 × PCIe 2.0 ×16 (Some H61 Motherboards Support PCIe 3.0)					1 × PCIe 2.0 ×16 or 2 × PCIe 2.0 ×8
Secondary PCIe		6 × PCIe 2.0 ×1	8 × PCIe 2.0 ×1
Conventional PCI support[b]		No	Yes			No
Intel Rapid Storage Technology (RAID)		No			Yes
Smart Response Technology		No						Yes
Ivy Bridge processor support		Yes	No			Yes
Intel Active Management, Trusted Execution, Anti-Theft, and vPro Technology		No			Yes	No
Release date		February 2011		May 2011		January 2011		May 2011
Maximum TDP		6.1 W
Chipset lithography		65 nm

Ivy Bridge family of chipsets

See also: Panther Point and List of Intel chipsets § LGA 1155

All Ivy Bridge chipsets and motherboards support both Sandy Bridge and Ivy Bridge CPUs. Ivy Bridge based processors will officially support up to DDR3-1600, up from DDR3-1333 of Sandy Bridge. Some consumer Ivy Bridge chipsets will also allow overclocking of K-series processors.^[11]

Name[12]		B75	Q75	Q77	C216	H77	Z75	Z77
Overclocking		CPU (Base Clock) + GPU					CPU + GPU + RAM	CPU + GPU + RAM
Allows using built-in GPU		Yes
Intel Clear Video Technology		Yes
RAID		No	Yes
Maximum USB ports	2.0	8	10
	3.0	4
Maximum SATA ports	2.0	5		4
	3.0	1		2
Main PCIe configuration[c]		1 × PCIe 3.0 ×16					1 × PCIe 3.0 ×16 or 2 × PCIe 3.0 ×8	1 × PCIe 3.0 ×16 or 2 × PCIe 3.0 ×8 or 1 × PCIe 3.0 ×8 and 2 × PCIe 3.0 ×4
Secondary PCIe		8 PCIe 2.0 ×1
Conventional PCI[b]		Yes				No [13]
Intel Rapid Storage Technology		No		Yes
Intel Anti-Theft Technology		Yes
Smart Response Technology		No		Yes			No	Yes
Intel vPro Platform Eligibility		No		Yes		No
Release date		April 2012[14]			May 2012	April 2012
Maximum TDP		6.7 W
Chipset lithography		65 nm[15]

NVMe support

Main article: NVM Express

A PC Games Hardware [de] user by the name of Mephisto_xD wrote an article on that website describing how to take UEFI modules from some Z97 motherboards and use them with an Z77-motherboard to make the latter support booting from an SSD using the NVM Express protocol, instead of the AHCI protocol.^[16] That article claims, the Z97 motherboards were the first to officially and fully support the NVMe protocol.

The modifications described also work with P67, B75 and other chipset motherboards.

Notes

1. USB 3.0 is not supported by any of these chipsets. Motherboard manufacturers may use external hardware to add USB 3.0 support.
2. Although some of the chipsets do not support conventional PCI, motherboard manufacturers may include support through the addition of third-party PCI bridges.
3. For PCIe 3.0 capability, the Ivy Bridge CPU must have the relevant PCIe 3.0 controller built in. However, some Ivy Bridge CPUs only have a PCIe 2.0 controller built in.

References

1. "Intel Core 2 gen CPUs and Socket 1155 Datasheet" (PDF). Intel. Archived from the original (PDF) on February 26, 2017. Retrieved September 26, 2012.
2. "2nd Gen Intel Core Processor, LGA1155 Socket" (PDF). Intel. Archived from the original (PDF) on July 13, 2011. Retrieved September 26, 2012.
3. "Ivy Bridge Quad-Core to Have 77W TDP, Intel Plans for LGA1155 Ivy Bridge Entry". TechPowerUp. October 18, 2011. Retrieved September 26, 2012.
4. "HP Elite 8200 SFF and 6200 Pro Business". Libreboot. Retrieved April 19, 2023.
5. Bell, Jared (July 25, 2011). "Sandy Bridge Memory Scaling: Choosing the Best DDR3". AnandTech. Retrieved September 26, 2012.
6. "Intel H61 Express Chipset". Intel. Retrieved September 26, 2012.
7. "Motherboards- ASUS P8H61 EVO". ASUS. Retrieved September 26, 2012.
8. "ARK - Compare Intel Products". Intel. Retrieved September 26, 2012.
9. "Intel H67 Express Chipset". Intel. Retrieved September 26, 2012.
10. "Intel SSD Caching Feature for Z68 Chipset Explored". VR Zone. April 25, 2011. Archived from the original on April 28, 2012. Retrieved September 26, 2012.
11. Vättö, Kristian (May 6, 2011). "Intel's Roadmap: Ivy Bridge, Panther Point, and SSDs". AnandTech. Retrieved September 26, 2012.
12. "ARK - Compare Intel Products". Intel. September 26, 2012.
13. "Intel 7 Series Chipset Family PCH: Datasheet". Intel. Retrieved December 2, 2014.
14. "Intel 7-Series Chipset Officially Debuts, Derived Desktop Board Products Launched". TechPowerUp. April 9, 2012. Retrieved September 26, 2012.
15. "ARK | Intel Z77 Express Chipset (Intel BD82Z77 PCH)". Intel. Retrieved September 26, 2012.
16. "Booten von einer NVMe-SSD mit Sandy-/Ivy-Bridge-Hardware". PC Games Hardware (in German). October 13, 2016. Retrieved November 13, 2022.

External links

• Intel desktop processor integration overview (LGA115x)