Summit Ridge, the enthusiast platform that will be the first product available with Zen, is based on the AM4 platform and processors will go up to 8-cores and 16-threads.
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At an event in San Francisco, AMD also revealed a few more details of the Zen’s low-level architecture, and in a multithreaded Blender rendering demo showed that an 8-core/16-thread “Summit Ridge” Zen CPU outperformed an 8C/16T Broadwell-E CPU (presumably the Core i7-6900K) at the same clockspeed. SMT is similar to Intel’s Hyper-Threading technology, which splits a single core into two virtual cores for more performance. The results are from the Ashes of the Singularity benchmark database, and so far, the performance of the AMD Zen is quite impressive, especially since it managed to compete with the Intel Core family CPUs.
The Summit Ridge block diagram, above, increases issue width and execution resources by 1.5x over Excavator, with a 1.75x instruction scheduler window increase over Excavator.
There is clearly a lot more for AMD to share about Zen but the announcement and showcase made this week with the early prototype products have solidified for me the capability and promise of this new microarchitecture. Probably the highlight of “The Path to Zen” event was the first-ever official Zen performance demo featuring AMD’s Summit Ridge vs. the Intel Broadwell-E.
AMD isn’t yet discussing Zen’s target clockspeed, but some leaked benchmarks last week purported to show an 8C/16T Zen engineering sample clocked at 2.8GHz base/3.2GHz turbo-which is pretty impressive when you consider that engineering samples are often clocked significantly lower than retail parts.
This methodology may seem unorthodox to some, but matching the chips clock-for-clock helps reveal their efficiencies. Tantalizingly, AMD says the 3GHz figure isn’t the final clock speed it expects production Zen chips to top out at, either.
Further information about the Zen architecture will be provided next week at Hot Chips 28. Notice that AMD didn’t give a percentage on the power reduction, so we’ll all just have to wait and see what holds. “This is the most exciting AMD (CPU) launch in a decade”, said Kevin Krewell, principal analyst with Tirias Research, who attended the event.
“They really have to execute”, said Reynolds in an interview.
Su said that the Zen launch would cap a big year for AMD. Gone are the shared, clustered multi-thread cores of the previous Bulldozer and Piledriver designs-Zen’s cores are stand-alone cores with SMT.
According to AMD, Zen sports improvements in three major areas: performance, throughput, and efficiency. Based strictly on the presentation, AMD shows a 40% IPC (Instructions Per Clock) over Vishera. AMD is also confident that Zen can scale to mobile and embedded devices, all on the same 14-nm GloFo process. “And I’m very happy to tell you we delivered that performance and the team is not stopping, they are full forward on the next-generation design”. The new Zen based AMD CPUs will run on the company’s new AM4 platform which will support DDR4 RAM and advanced I/O.
Here’s what 128 threads of computing looks like on a dual-processor AMD Naples-based server.
Zen isn’t just coming to enthusiast desktops. The demonstration of a 32-core, 64-thread Naples server system-on-a-chip (SoC) also showed significant performance and efficiency gains.
Above: Summit Ridge is the first instance of AMD’s Zen series chips.
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AMD is using Globalfoundries, a contract chip manufacturer, to manufacture the chips. The Summit Ridge chips are expected to debut in the the fourth quarter, while Naples is expected to debut in the first half of 2017, followed by laptop chips in the second half of 2017. The reasons behind the queue being able to dispatch more per cycle is if the decoder can supply an instruction which then falls into two micro-ops (which makes the instruction vs micro-op definitions even muddier).
