LGA 2011 followed by LGA 2011-v3
Physical design and socket generations
Intel CPU sockets use the so-called Independent Loading Mechanism (ILM) retention device to apply the specific amount of uniform pressure required to correctly hold the CPU against the socket interface. As part of their design, ILMs have differently placed protrusions which are intended to mate with cutouts in CPU packagings.  These protrusions, also known as ILM keying, have the purpose of preventing installation of incompatible CPUs into otherwise physically compatible sockets, and preventing ILMs to be mounted with a 180-degree rotation relative to the CPU socket.Different variants (or generations) of the LGA 2011 socket and associated CPUs come with different ILM keying, which makes it possible to install CPUs only into generation-matching sockets.  CPUs that are intended to be mounted into LGA 2011-0 (R), LGA 2011-1 (R2) or LGA 2011-v3 (R3) sockets are all mechanically compatible regarding their dimensions and ball pattern pitches, but the designations of contacts are different between generations of the LGA 2011 socket and CPUs, which makes them electrically and logically incompatible.  Original LGA 2011 socket is used for Sandy Bridge-E/EP and Ivy Bridge-E/EP processors, while LGA 2011-1 is used for Ivy Bridge-EX (Xeon E7 v2) and Haswell-EX (Xeon E7 V3) CPUs, which were released in February 2014 and May 2015, respectively. LGA 2011-v3 socket is used for Haswell-E and Haswell-EP CPUs, which were released in August and September 2014, respectively.Two types of ILM exist, with different shapes and heatsink mounting hole patterns, both with M4 x 0.7 threads: square ILM (80×80 mm mounting pattern), and narrow ILM (56×94 mm mounting pattern).  Square ILM is the standard type, while the narrow one is alternatively available for space-constrained applications. A matching heatsink is required for each ILM type.Haswell-EP (Xeon E5 v3)
Server processors for the LGA 2011-v3 socket are listed in the tables below. As one of the significant changes from the previous generation, they support DDR4 memory. All processors are released on September 8, 2014, unless noted otherwise.