While being ARMv8-A instruction set architecture compliant, the K12 is expected to be entirely custom designed targeting server, embedded, and semi-custom markets. While ARM architecture development continued, products based on K12 were subsequently delayed with no release planned, in preference to the development of AMD's x86-based Zen microarchitecture. Zen-based CPUs and APUs Zen is a new architecture for x86-64 based Ryzen series of CPUs and APUs, introduced in 2017 by AMD and built from the ground up by a team led by Jim Keller, beginning with his arrival in 2012, and taping out before his departure in September 2015. One of AMD's primary goals with Zen was an IPC increase of at least 40%, however in February 2017 AMD announced that they had actually achieved a 52% increase. Processors made on the Zen architecture are built on the 14 nm FinFET node and have a renewed focus on single-core performance and HSA compatibility. Previous processors from AMD were either built in the 32 nm process ("Bulldozer" and "Piledriver" CPUs) or the 28 nm process ("Steamroller" and "Excavator" APUs). Because of this, Zen is much more energy efficient. The Zen architecture is the first to encompass CPUs and APUs from AMD built for a single socket (Socket AM4). Also new for this architecture is the implementation of simultaneous multithreading (SMT) technology, something Intel has had for years on some of their processors with their proprietary hyper-threading implementation of SMT. This is a departure from the "Clustered MultiThreading" design introduced with the Bulldozer architecture. Zen also has support for DDR4 memory. AMD released the Zen-based high-end Ryzen 7 "Summit Ridge" series CPUs on March 2, 2017, mid-range Ryzen 5 series CPUs on April 11, 2017, and entry level Ryzen 3 series CPUs on July 27, 2017. AMD later released the Epyc line of Zen derived server processors for 1P and 2P systems. In October 2017, AMD released Zen-based APUs as Ryzen Mobile, incorporating Vega graphics cores. In January 2018 AMD has announced their new lineup plans, with Ryzen 2. AMD launched CPUs with the 12nm Zen+ microarchitecture in April 2018, following up with the 7nm Zen 2 microarchitecture in June 2019, including an update to the Epyc line with new processors using the Zen 2 microarchitecture in August 2019, and Zen 3 slated for release in Q3 2020. As of 2019, AMD's Ryzen processors were reported to outsell Intel's consumer desktop processors.