The biggest news has to do with Zen, the new x86-compatible CPU core meant to replace Bulldozer family. AMD told us Zen about the technical details of the new architecture, but hinted about some vaguely encouraging details – mostly about time lines.
Zen will be a high-performance core intended to compete against Chipzilla’s best. In fact AMD expects its core to deliver about 40 percent higher performance per clock cycle than Bulldozer.
Zen looks a bit like K8 and Broadwell and is less about speed than what you can do with it.
Also, the first Zen-based cores are just the beginning. Future “Zen+” variants of this architecture should improve per-clock performance even further.
The Zen core will have simultaneous multithreading (SMT). Zen will stop at two threads per core, like today’s big Intel cores. Dual threads puts AMD on a more equal footing with Intel from a marketing standpoint.
Zen has a “high-bandwidth, low-latency cache system.” This is better than Bulldozer which has always suffered from a caches shortage. They clearly don’t perform as well in directed subsystem tests as the caches on recent Intel CPUs.
Zen will be in the shops in 2016, and those chips will be based on a chip fabrication process that uses FinFETs.
FinFETs will mean a faster switching speed and lower voltage operation than traditional planar transistors. AMD didn’t reveal the specific process to be used but they must be 14- and 16-nm FinFET processes at Samsung, GlobalFoundries, and TSMC.
Zen-based FX processors will be supported by a new AM4 platform that includes support for DDR4 memory. This same AM4 platform will also support smaller APU chips, unifying the company’s desktop offerings around a single socket.
AMD apparently had to prioritize this one chip over other options. The company’s 2016 APU products for desktops and mobile systems will not yet incorporate the Zen core. Also, the schedule for the K12 core, the ARM-compatible sister to Zen, has been pushed back to 2017.
CEO Lisu Su further revealed that Project Skybridge, the effort to make ARM- and x86-compatible CPUs share the same sockets and motherboards, has been nixed, reputedly due to lack of customer demand.