AMD Zen 2 Microarchitecture Analysis: Ryzen 3000 and EPYC Romeby Dr. Ian Cutress on June 10, 2019 7:22 PM EST
- Posted in
- Infinity Fabric
- PCIe 4.0
- Zen 2
- Ryzen 3000
- Ryzen 3rd Gen
Editor's Note: With Zen 2 set to launch tomorrow (7/7), here's our architecture analysis from last month for some timely background information.
We have been teased with AMD’s next generation processor products for over a year. The new chiplet design has been heralded as a significant breakthrough in driving performance and scalability, especially as it becomes increasingly difficult to create large silicon with high frequencies on smaller and smaller process nodes. AMD is expected to deploy its chiplet paradigm across its processor line, through Ryzen and EPYC, with those chiplets each having eight next-generation Zen 2 cores. Today AMD went into more detail about the Zen 2 core, providing justification for the +15% clock-for-clock performance increase over the previous generation that the company presented at Computex last week.
AMD’s Zen 2 Product Portfolio
The current products that AMD has announced that have Zen 2 cores include the Ryzen 3rd Generation consumer CPUs, known as the Ryzen 3000 family, and AMD’s next generation enterprise EPYC processor, known as Rome. As of today, AMD has announced explicit details of six consumer Ryzen 3000 processors, including core counts, frequencies, memory support, and power. Details about the server processor, aside from some peak values, are expected in due course over the next few months.
|AMD 'Matisse' Ryzen 3000 Series CPUs|
|Ryzen 9||3950X||16C||32T||3.5||4.7||8 MB||64 MB||16+4+4||3200||105W||$749|
|Ryzen 9||3900X||12C||24T||3.8||4.6||6 MB||64 MB||16+4+4||3200||105W||$499|
|Ryzen 7||3800X||8C||16T||3.9||4.5||4 MB||32 MB||16+4+4||3200||105W||$399|
|Ryzen 7||3700X||8C||16T||3.6||4.4||4 MB||32 MB||16+4+4||3200||65W||$329|
|Ryzen 5||3600X||6C||12T||3.8||4.4||3 MB||32 MB||16+4+4||3200||95W||$249|
|Ryzen 5||3600||6C||12T||3.6||4.2||3 MB||32 MB||16+4+4||3200||65W||$199|
The Zen 2 design paradigm, compared to the first generation of Zen, has changed significantly. The new platform and core implementation is designed around small 8-core chiplets built on TSMC’s 7nm manufacturing process, and measure around 74-80 square millimeters. On these chiplets are two groups of four-cores arranged in a ‘core complex’, or CCX, which contains those four cores and a set of L3 cache – the L3 cache is doubled for Zen 2 over Zen 1.
Each full CPU, regardless of how many chiplets it has, is paired with a central IO die through Infinity Fabric links. The IO die acts as the central hub for all off-chip communications, as it houses all the PCIe lanes for the processor, as well as memory channels, and Infinity Fabric links to other chiplets or other CPUs. The IO die for the EPYC Rome processors is built on Global Foundries' 14nm process, however the consumer processor IO dies (which are smaller and contain fewer features) are built on the Global Foundries 12nm process.
The consumer processors, known as ‘Matisse’ or Ryzen 3rd Gen or Ryzen 3000-series, will be offered with up to two chiplets for sixteen cores. AMD is launching six versions of Matisse on July 7th, from six cores to sixteen cores. The six and eight-core processors have one chiplet, while above this the parts will have two chiplets, but in all cases the IO die is the same. This means that every Zen 2 based Ryzen 3000 processor will have access to 24 PCIe 4.0 lanes and dual channel memory. Based on the announcements today, the prices will range from $199 for the Ryzen 5 3600, up to $700+ for the sixteen core (we’re waiting on final confirmation of this price).
The EPYC Rome processors, built on these Zen 2 chiplets, will have up to eight of them, enabling a platform that can support up to 64 cores. As with the consumer processors, no chiplet can communicate directly with each other – each chiplet will only connect directly to the central IO die. That IO die houses links for eight memory channels, and up to 128 lanes of PCIe 4.0 connectivity.
Before diving into the new product line, it is worth recapping where we currently sit in AMD’s planned roadmap.
In previous roadmaps, showcasing AMD’s movement from Zen to Zen 2 and Zen 3, the company has explained that this multi-year structure will showcase Zen in 2017, Zen 2 in 2019, and Zen 3 by 2021. The cadence isn’t exactly a year, as it has depended on AMD’s design and manufacturing abilities, as well as agreements with its partners in the foundries and the current market forces.
AMD has stated that its plan for Zen 2 was to always launch on 7nm, which ended up being TSMC’s 7nm (Global Foundries wasn’t going to be ready in time for 7nm, and ultimately pulled the plug). The next generation Zen 3 is expected to align with an updated 7nm process, and at this point AMD has not made any comment about a potential ‘Zen 2+’ design in the works, although at this point we do not expect to see one.
Beyond Zen 3, AMD has already stated that Zen 4 and Zen 5 are currently in various levels of their respective design stages, although the company has not committed to particular time frames or process node technologies. AMD has stated in the past that the paradigms of these platforms and processor designs are being set 3-5 years in advance, and the company states it has to make big bets every generation to ensure it can remain competitive.
For a small insight into Zen 4, in an interview with Forrest Norrod, SVP of AMD’s Enterprise, Embedded, and Semi-Custom group, at Computex, he exclusively revealed to AnandTech the code name of AMD’s Zen 4 EPYC processor: Genoa.
|AMD EPYC CPU Codenames|
|1st||2017||Naples||32 x Zen 1|
|2nd||2019||Rome||64 x Zen 2|
|3rd||2020||Milan||? x Zen 3|
|4th||?||Genoa||? x Zen 4|
|5th||?||?||? x Zen 5|
Forrest explained that the Zen 5 code name follows a similar pattern, but would not comment on the time frame for the Zen 4 product. Given that the Zen 3 design is expected mid-2020, that would put a Zen 4 product for late 2021/early 2022, if AMD follows its cadence. How this will play into AMD’s consumer roadmap plans is unclear at this point, and will depend on how AMD approaches its chiplet paradigm and any future adjustments to its packaging technology in order to enable further performance improvements.
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Smell This - Sunday, June 16, 2019 - link
it might be 12- to 16 IF links or, another substrate ?
Targon - Thursday, June 13, 2019 - linkEpyc and Ryzen CCX units are TSMC, the true CPU cores. The I/O unit is the only part that comes from Global Foundries, and is probably at TSMC just to satisfy the contracts currently in place.
YukaKun - Monday, June 10, 2019 - link"Users focused on performance will love the new 16-core Ryzen 9 3950X, while the processor seems nice an efficient at 65W, so it will be interesting so see what happens at lower power."
Shouldn't that be 105W?
And great read as usual.
jjj - Monday, June 10, 2019 - linkThe big problem with this platform is that ST perf per dollar gains are from zero to minimal, depending on SKU.
They give us around 20% ST gains (IPC+clocks) but at a cost. Would rather have 10-15% gains for free than to pay for 20%. Pretty much all SKUs need a price drop to become exciting, some about 50$, some a bit less and the 16 cores a lot more.
Got to wonder about memory BW with the 16 cores. 2 channels with 8 cores is one thing but at 16 cores, it might become a limiting factor here and there.
Threska - Tuesday, June 11, 2019 - linkThat could be said of any processor. "Yeah, drop the price of whatever it is and we'll love you for it." Improvements cost, just like DVD's costed more than VHS.
jjj - Tuesday, June 11, 2019 - linkIn the semi business the entire point is to offer significantly more perf per dollar every year. That's what Moore's Law was, 2x the perf at same price every 2 years. Now progress is slower but consumers aren't getting anything anymore.
And in pretty much all tech driven areas, products become better every year, even cars. When there is no innovation, it means that the market is dysfunctional. AMD certainly does not innovate here, except on the balance sheet. Innovation means that you get better value and that is missing here. TSMC gives them more perf per dollar, they have additional gains from packaging but those gains do not trickle down to us. At the end of the day even Intel tries to offer 10-15% perf per dollar gains every cycle.
AlyxSharkBite - Tuesday, June 11, 2019 - linkThat’s not Moore’s Law at all. It stated that the number of transistors would double. Also it’s been dead a while
Sandy bridge 4c 1.16b
Coffee lake 4c is 2.1b (can’t compare the 6c or 8c)
And that’s a lot more than 2 years.
mode_13h - Tuesday, June 11, 2019 - linkYeah, but those two chips occupy different market segments. So, you should compare Sandybridge i7 vs. Coffelake i7.
Teutorix - Tuesday, June 11, 2019 - linkThe number of transistors in an IC, not the number of transistors per CPU core. This is an important distinction since a CPU core in Moore's day had very little in it besides registers and an ALU. They didn't integrate FPUs until relatively recently.
It's about overall transistor density, nothing more. You absolutely can compare an 8c to a 4c chip, because they are both a single IC.
An 8 core coffee lake chip is 20% smaller than a quad core sandy bridge chip. That's double the CPU cores, double the GPU cores, with probably a massive increase in the transistors/core also.
Moore's law had a minor slowdown with intel stuck at 14nm but its not dead.
Wilco1 - Tuesday, June 11, 2019 - linkMoore's Law is actually accelerating. Just not at Intel. See https://en.wikipedia.org/wiki/Transistor_count - the largest chips now have ~20 Billion transistors, and with 7nm and 5nm it looks like we're getting some more doublings soon.