Zen (microarchitecture)
Zen is the codename for a family of computer processor microarchitectures from AMD, first launched in February 2017 with the first generation of its Ryzen CPUs.

Comparison

History

First generation

The first generation Zen was launched with the Ryzen 1000 series of CPUs (codenamed Summit Ridge) in February 2017. The first Zen-based preview system was demonstrated at E3 2016, and first substantially detailed at an event hosted a block away from the Intel Developer Forum 2016. The first Zen-based CPUs reached the market in early March 2017, and Zen-derived Epyc server processors (codenamed "Naples") launched in June 2017 and Zen-based APUs (codenamed "Raven Ridge") arrived in November 2017. This first iteration of Zen utilized Global Foundries' 14 nm manufacturing process.

Second generation

Zen+ was first released in April 2018, powering the second generation of Ryzen processors, known as Ryzen 2000 (codenamed "Pinnacle Ridge") for mainstream desktop systems, and Threadripper 2000 (codenamed "Colfax") for high-end desktop setups. This generation used Global Foundries' 12 nm process, an enhanced version of their 14 nm node.

Third generation

The Ryzen 3000 series CPUs were released on July 7, 2019, while the Zen 2-based Epyc server CPUs (codename "Rome") were released on August 7, 2019. Zen 2 also powered a line of desktop APUs marketed as Ryzen 4000. These were the first consumer CPUs using TSMC's 7 nm process node. Zen 2 introduced the chiplet based architecture, where all desktop, workstation and server CPUs utilized the same core chiplets. The IO for these processors was taken care of by an IO die, separate from the processing cores. The IO die used by Matisse processors was a small chip on GF 12 nm, where as the IO die utilized for Threadripper and Epyc was much larger, able to handle more IO. These chiplets were linked by AMD's own second generation Infinity Fabric, allowing a low-latency interconnect between the cores and their IO. Matisse was limited to two 8-core chiplets and Threadripper/Epyc was limited to eight 8-core chiplets. The processing cores in the chiplets were organized in CCXs (Core Complexes) of four cores, linked together to form a single eight core CCD (Core Chiplet Die).

Fourth generation

Zen 3 was released on November 5, 2020, using a more matured 7 nm manufacturing process, powering Ryzen 5000 series CPUs & APUs (codename "Vermeer" (CPU) and "Cézanne" (APU)) and Epyc processors (codename "Milan"). Zen 3's main performance gain over Zen 2 is the introduction of a unified CCX, which means that each core chiplet is now composed of eight cores with access to 32MB of cache, instead of two sets of four cores with access to 16MB of cache each.

Zen 3D was officially previewed on May 31, 2021 and confirmed for release in the first half of 2022 in AMD's Computex 2021 presentation. Zen 3D will differ from Zen 3 in that it will include V-cache, 3D-stacked L4 cache. This added cache should bring a 15% performance increase in gaming applications on average.

Zen 3D for server, codenamed Milan-X was announced in Nov 8th 2021's AMD Accelerated Data Center Premiere Keynote. It should bring a 50% increase in select datacenter applications over Zen 3's Milan CPUs while maintaining socket compatibility with them.

Fifth generation 
Zen 4 for server, codename Genoa, was officially unveiled at AMD's Accelerated Data Center Premiere Keynote on Nov 8th 2021. It will have up to 96 Zen 4 cores and will support both PCIE 5.0 and DDR5.

Furthermore, Zen 4 Cloud (a variant of Zen 4), abbreviated to Zen 4c and codenamed Bergamo, was also announced. Zen 4c is designed to have significantly greater density than standard Zen4 while delivering greater power efficiency. This is achieved by redesigning Zen4's cache (presumably removing a certain amount of L2 and L3 cache) to maximise density and compute throughput. Bergamo will have up to 128 Zen 4c cores and will be socket-compatible with Genoa.

Both Zen 4 and Zen 4 Cloud will be manufactured on a non-specified variety of TSMC 5 nm and are slated to launch in 2022.

See also
 Threadripper
 Epyc
Intel Core

References

Advanced Micro Devices microarchitectures
Computer-related introductions in 2017
X86 microarchitectures