AMD Zen CPU Core Testing “Met All Expectation” – No “Significant Bottlenecks” Found
The web has recently been abuzz with rumors about AMD's latest high performance x86 CPU core inception code named "Zen" but one particular rumor caught our attention.
According to some of the whispers we've heard as of late, AMD design engineers have maintained a goal for Zen to be competitive with Intel's future offerings from the very beginning. The engineering teams are said to have already tested Zen and that test chips of the new CPU core have so far "met all expectation" with no "significant bottlenecks" in the microarchitecture being found.
We haven't been able to verify these claims and as such would advise all readers to take this rumor with the usual grain of NaCl.
[UPDATED - 2016-05-20]
AMD's President & CEO Lisa Su confirmed that Zen has exceeded expectations throughout testing and validation and will deliver a performance per clock improvement that exceeds 40% versus the company's most recent high performance CPU microarchitecture code named Excavator.
This comes off the heels of the AIDA64 changelog which now includes Zen based "Summit Ridge" and "Raven Ridge" FX CPUs and APUs respectively. Last month was also very intriguing, with revelations about AMD's Zen and K12 CPU cores taping out as well as the wealth of information which was revealed through an official AMD Linux patch that detailed many aspects of the Zen microarchitecture and what the CPU core is capable of.
What We Know So Far About AMD's Zen Microarchitecture
We first broke the news about AMD's next generation high performance core back in September of last year. At which point AMD's then CEO Rory Read revealed the code name for the company's upcoming high performance x86 CPU microarchitecture. Prior to that we only had knowledge of Zen's sister ARMv8 core code named K12.
As of late AMD has been slightly more generous with information about its brand new microarchitecture. Back in May AMD announced that it was preparing an entirely new line-up of FX CPUs and a brand new platform 'AM4". We learned that the new family of FX processors code named "Summit Ridge" would feature an entirely new socket and an updated feature set including DDR4 memory support. More importantly we learned that the new platform would feature mainstream CPUs with "high core counts" - rumored to be up to eight cores - and "SMT" support.
Two months later we learned that AMD was also working on a monstrous High Performance Computing APU with 16 Zen cores and a huge integrated GPU in addition to stacked High Bandwidth Memory. We also learned that AMD is planning to introduce high performance server CPUs with up to 32 Zen CPU cores. Hearing about all of those different SKUs is jolly exciting, but it was also quite frustrating as no-one really had a clear idea of what to expect from Zen. That is until AMD revealed a whopper at its Financial Analyst Day earlier this year, which is that Zen will have a 40% instruction per clock improvement over its predecessor "Excavator".
AMD's Zen CPU Core Coming in 2016 - Features FinFET Process, SMT And New Cache System
Zen will be AMD's successor to the Bulldoze family of cores. It will be the first ever CPU core from the company to adopt simultaneous multithreading. It's also the company's first entirely new CPU core design following the Bulldozer family of cores which debuted in 2011 and was the company's first ever design to feature clustered multithreading .
In addition to SMT, Zen also features a new high-bandwidth low latency cache system. A vital improvement over the previous generation of cores. Since subpar cache performance was one of the primary pitfalls of AMD's Bulldozer CPU microarchitecture. The new CPU core is designed for and will be manufactured on an advanced FinFET process. Which would allow the CPU core to scale from low power mobile applications to high performance desktop and enterprise markets.
Zen To Feature A 40% Instructions Per Clock Improvement Over Excavator
Mark Papermaster, AMD's Chief Technology Officer revealed that the company plans to introduce a huge IPC improvement with Zen over AMD's latest generation "Excavator" x86 core. A 40% increase in IPC would represent the largest jump in IPC ever for the company, an improvement which Mark Papermaster claimed he had not seen "anywhere in the industry".
Papermaster also made it a point to highlight that this 40% performance improvement figure is independent from the manufacturing process. So it's a permanent architectural performance improvement that will always be present regardless of the process node.
Zen will be featured in AMD's enthusiast CPU product line in 2016. Lisa Su confirmed that the new CPU architecture will be arriving to desktop FX CPUs first and to servers second. Succeeding Zen will be Zen+ cores. Which will feature evolutionary improvement over Zen. The company will introduce a new socket in 2016 dubbed AM4 that will house products spanning from high performance CPUs to mainstream APUs based on Zen and next generation FinFET GCN based GPUs.
The new family of high performance FX CPUs which appeared in previous leaks as "Summit Ridge" will feature SMT CPUs with high core counts and DDR4 memory support. The platform will be based on the new AM4 socket and a new yet undisclosed chipset. Unconfirmed leaks indicate that Summit Ridge will feature CPUs with up to 8 Zen cores and 12MB of L2 and L3 cache, but that is yet to be confirmed.