Manufacturing process Processors based on Zen use 14 nm
FinFET silicon. These processors are reportedly produced at
GlobalFoundries. Prior to Zen, AMD's smallest process size was 28 nm, as utilized by their
Steamroller and
Excavator microarchitectures. The immediate competition, Intel's
Skylake and
Kaby Lake microarchitecture, are also fabricated on 14 nm FinFET; though Intel planned to begin the release of
10 nm parts later in 2017. Intel was unable to reach this goal, and in 2021, only mobile chips have been produced with the 10nm process. In comparison to Intel's 14 nm FinFET, AMD claimed in February 2017 the Zen cores would be 10% smaller. Intel has later announced in July 2018 that 10nm mainstream processors should not be expected before the second half of 2019. For identical designs, these
die shrinks would use less current (and power) at the same frequency (or voltage). As CPUs are usually power limited (typically up to ~125W, or ~45W for mobile), smaller transistors allow for either lower power at the same frequency, or higher frequency at the same power.
Performance One of Zen's major goals in 2016 was to focus on performance per-core, and it was targeting a 40% improvement in
instructions per cycle (IPC) over its predecessor.
Excavator, in comparison, offered 4–15% improvement over previous architectures. AMD announced the final Zen microarchitecture actually achieved 52% improvement in IPC over Excavator. The inclusion of SMT also allows each core to process up to two threads, increasing processing throughput by better use of available resources. The Zen processors also employ sensors across the chip to dynamically scale frequency and voltage. This allows for the maximum frequency to be dynamically and automatically defined by the processor itself based upon available cooling. AMD has demonstrated an 8-core/16-thread Zen processor outperforming an equally-clocked
Intel Broadwell-E processor in
Blender rendering This difference was corrected in
Zen 2.
Memory Zen supports
DDR4 memory (up to eight channels) and
ECC. Pre-release reports stated APUs using the Zen architecture would also support
High Bandwidth Memory (HBM). However, the first demonstrated APU did not use HBM. Previous APUs from AMD relied on shared memory for both the GPU and the CPU.
Power consumption and heat output Processors built at the 14 nm node on FinFET silicon should show reduced power consumption and therefore heat over their 28 nm and 32 nm non-FinFET predecessors (for equivalent designs), or be more computationally powerful at equivalent heat output/power consumption. Zen also uses
clock gating, The Secure Encrypted Virtualization (SEV) feature allows the memory contents of a virtual machine (VM) to be transparently encrypted with a key unique to the guest VM. The memory controller contains a high-performance encryption engine which can be programmed with multiple keys for use by different VMs in the system. The programming and management of these keys is handled by the AMD Secure Processor firmware which exposes an API for these tasks. On client processors, SME and SEV are offered on AMD's Ryzen Pro series.
Connectivity Incorporating much of the
southbridge into the
SoC, the Zen CPU includes
SATA,
USB, and
PCI Express NVMe links. This can be augmented by available
Socket AM4 chipsets which add connectivity options including additional SATA and USB connections, and support for
AMD's Crossfire and
Nvidia's SLI. AMD, in announcing its Radeon Instinct line, argued that the upcoming Zen-based Naples server CPU would be particularly suited for building
deep learning systems. The 128
PCIe lanes per Naples CPU allows for eight
Instinct cards to connect at PCIe x16 to a single CPU. This compares favorably to the Intel Xeon line, with only 40 PCIe lanes. == Products == The Zen architecture is used in the current-generation desktop
Ryzen CPUs. It is also in
Epyc server processors (successor of
Opteron processors), and APUs. The first desktop processors without graphics processing units (codenamed "Summit Ridge") were initially expected to start selling at the end of 2016, according to an AMD roadmap; with the first mobile and desktop processors of the
AMD Accelerated Processing Unit type (codenamed "Raven Ridge") following in late 2017. AMD officially delayed Zen until Q1 of 2017. In August 2016, an early demonstration of the architecture showed an 8-core/16-thread engineering sample CPU at 3.0 GHz. On March 2, 2017, AMD officially launched the first Zen architecture-based octacore Ryzen desktop CPUs. The final clock speeds and TDPs for the 3 CPUs released in Q1 of 2017 demonstrated significant performance-per-watt benefits over the previous
K15h (Piledriver) architecture. The octacore Ryzen desktop CPUs demonstrated performance-per-watt comparable to Intel's Broadwell octacore CPUs. In March 2017, AMD also demonstrated an engineering sample of a server CPU based on the Zen architecture. The CPU (codenamed "Naples") was configured as a dual-socket server platform with each CPU having 32 cores/64 threads. (And three more SKUs in December that year.)
R1000 In 2019, AMD announced the R1000 series of embedded Zen+Vega APUs.
Server processors AMD announced in March 2017 that it would release a server platform based on Zen, codenamed Naples, in the second quarter of the year. The platform include 1- and 2-socket systems. The CPUs in multi-processor configurations communicate via AMD's Infinity Fabric. Each chip supports eight channels of memory and 128 PCIe 3.0 lanes, of which 64 lanes are used for CPU-to-CPU communication through Infinity Fabric when installed in a dual-processor configuration. AMD officially revealed Naples under the brand name Epyc in May 2017. On June 20, 2017, AMD officially released the Epyc 7000 series CPUs at a launch event in Austin, Texas.
Embedded server processors In February 2018, AMD also announced the EPYC 3000 series of embedded Zen CPUs. ==See also==