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.
Xeon
Dunnington – the last CPU of the Penryn generation and Intel's first multi-core (above two) die – features a single-die six- (or "hexa-") core design with three unified 3 MB L2 caches (resembling three merged 45 nm dual-core Wolfdale dies), and 96 kB L1 cache (Data) and 16 MB of L3 cache. It features 1066 MHz FSB, fits into the Tigerton's mPGA604 socket, and is compatible with both the Intel Caneland and IBM X4 chipsets. These processors support DDR2-1066 (533 MHz), and have a maximum TDP below 130 W. They are intended for blades and other stacked computer systems. Availability was scheduled for the second half of 2008. It was followed shortly by the Nehalem microarchitecture. Total transistor count is 1.9 billion.