LGA 2011 replaces LGA 1356
LGA 2011, also called Socket R, is a CPU socket by Intel released on November 14, 2011. It launched along with LGA 1356 to replace its predecessor, LGA 1366 (Socket B) and LGA 1567. While LGA 1356 was designed for dual-processor or low-end servers, LGA 2011 was designed for high-end desktops and high-performance servers. The socket has 2011 protruding pins that touch contact points on the underside of the processor.
The LGA 2011 socket uses QPI to connect the CPU to additional CPUs. DMI 2.0 is used to connect the processor to the PCH. The memory controller and 40 PCI Express (PCIe) lanes are integrated on the CPU. On a secondary processor an extra ×4 PCIe interface replaces the DMI interface. As with its predecessor LGA 1366, there is no provisioning for integrated graphics.  This socket supports four DDR3 or DDR4 SDRAM memory channels with up to three unbuffered or registered DIMMs per channel, as well as up to 40 PCI Express 2.0 or 3.0 lanes. LGA 2011 also has to ensure platform scalability beyond eight cores and 20 MB of cache.The LGA 2011 socket is used by Sandy Bridge-E/EP and Ivy Bridge-E/EP processors with the corresponding X79 (E –  enthusiast class) and C600-series (EP –  Xeon class) chipsets. It and LGA 1155 are the two last Intel sockets to support Windows XP and Windows Server 2003.
LGA 2011-1 (Socket R2), an updated generation of the socket and the successor of LGA 1567, is used for Ivy Bridge-EX (Xeon E7 v2), Haswell-EX (Xeon E7 v3) and Broadwell-EX (Xeon E7 v4) CPUs, which were released in February 2014, May 2015 and July 2016, respectively.
LGA 2011-v3 (Socket R3, also referred to as LGA 2011-3) is another updated generation of the socket, used for Haswell-E and Haswell-EP CPUs and Broadwell-E, which were released in August and September 2014, respectively. Updated socket generations are physically similar to LGA 2011, but different electrical signals, ILM keying and integration of DDR4 memory controller rather than DDR3 prevent backward compatibility with older CPUs.In the server market, it was succeeded by LGA 3647, when in high-end desktop and workstation markets its successor is LGA 2066. Xeon E3 family of processors, later renamed Xeon E, uses consumer-grade sockets.