LGA s1151 CPU Socket Pinout

The LGA 1151 processor socket, also called Socket H4, is a socket for Intel processors that supports Skylake, Kaby Lake and later Coffee Lake and Coffee Lake Refresh architecture processors. Socket H4 is designed as a replacement for the LGA 1150 socket (known as Socket H3) and has 1151 spring-loaded contacts to contact the processor pads.

Motherboards with an LGA 1151 socket usually only support two channels of DDR4 RAM. Some LGA 1151 motherboards (for sixth-generation Skylake processors) only support DDR3 or DDR3L memory.

The LGA 1151 cooling system mount is compatible with LGA 1155 and LGA 1150 sockets.

Pinout of the Intel LGA 1151 (SkyLake, Kaby Lake) processor socket of the 6th and 7th series on motherboards with Intel 100th and 200th series chipsets:

For a description of the LGA 1151 socket pins for Intel processors of the SkyLake microarchitecture and its successor Kaby Lake, see the instructions on pages 131-164, in table No. 9-1.

Pinout of the Intel LGA 1151 (Coffee Lake and Coffee Lake Refresh) processor socket of the 8th and 9th series on motherboards with Intel 300 series chipsets:

For a description of the LGA 1151 socket pins for Intel processors of the Coffee Lake microarchitecture and its successor Coffee Lake Refresh, see the instructions.

It is known that Intel Coffee Lake processors, despite using the LGA 1151 socket, are supported exclusively by new motherboards based on 300 series chipsets. According to Intel representatives, the lack of backward compatibility with motherboards based on Intel 100 and 200 series chipsets is due to a redesigned power supply for the new processors, designed to ensure stable operation and overclocking of six-core Intel 8 and 9 series processors.

If we look specifically at what are the differences between the LGA 1151 (SkyLake, Kaby Lake) and LGA 1151 (Coffee Lake) sockets, we will notice a number of differences in the contact pads. In the new version of the LGA 1151 (Coffee Lake) socket, Intel has increased the number of Vss (ground) and Vcc (power) pads. At the same time, Intel reduced the number of reserved pads - RSVD. The number of these pads in the new socket is as follows:

• Vss – 378 pcs. (14 more);
• Vcc – 128 pcs. (18 more);
• RSVD – 25 pcs. (21 less).

The differences between the LGA 1151 (SkyLake, Kaby Lake) and LGA 1151 (Coffee Lake) sockets are in two groups of contact pads:

The first group of modified pads for LGA 1151 (SkyLake, Kaby Lake) and LGA 1151 (Coffee Lake) sockets:

The second group of modified contact pads:

Thus, the lack of support for Coffee Lake processors on older motherboards based on Intel 100- and 200-series chipsets is caused by significant changes in the design of the contact pads of the LGA 1151 (Coffee Lake) socket, and not only by Intel’s desire to make money on the sale of chipsets and new motherboards plat.