Xeon
Introduced in May 2013, Xeon E3-12xx v3 is the first Xeon series based on the Haswell microarchitecture. It uses the new LGA 1150 socket, which was introduced with the desktop Core i5/i7 Haswell processors, incompatible with the LGA 1155 that was used in Xeon E3 and E3 v2. As before, the main difference between the desktop and server versions is added support for ECC memory in the Xeon-branded parts. The main benefit of the new microarchitecture is better power efficiency.
Pleiades (supercomputer)
In late 2014, more Westmere nodes were removed to make room for new Intel Xeon Haswell processors, increasing the theoretical processing power by one petaflop to 4.49 petaflops. In January 2015, additional Haswell nodes were installed and released to users, giving Pleiades a new peak theoretical processing capacity of 5.35 petaflops. An upgrade, completed in June 2016, replaced all remaining racks containing nodes with six-core Intel Xeon X5670 (Westmere) processors with racks containing nodes using 14-core Intel Xeon E5-2680v4 (Broadwell) processors. This improved the theoretical peak performance to 7.25 petaflops.