AMD Zen 2 Microarchitecture Analysis: Ryzen 3000 and EPYC Rome
by Dr. Ian Cutress on June 10, 2019 7:22 PM EST- Posted in
- CPUs
- AMD
- Ryzen
- EPYC
- Infinity Fabric
- PCIe 4.0
- Zen 2
- Rome
- Ryzen 3000
- Ryzen 3rd Gen
Performance Claims of Zen 2
At Computex, AMD announced that it had designed Zen 2 to offer a direct +15% raw performance gain over its Zen+ platform when comparing two processors at the same frequency. At the same time, AMD also claims that at the same power, Zen 2 will offer greater than a >1.25x performance gain at the same power, or up to half power at the same performance. Combining this together, for select benchmarks, AMD is claiming a +75% performance per watt gain over its previous generation product, and a +45% performance per watt gain over its competition.
These are numbers we can’t verify at this point, as we do not have the products in hand, and when we do the embargo for benchmarking results will lift on July 7th. AMD did spend a good amount of time going through the new changes in the microarchitecture for Zen 2, as well as platform level changes, in order to show how the product has improved over the previous generation.
It should also be noted that at multiple times during AMD’s recent Tech Day, the company stated that they are not interested in going back-and-forth with its primary competition on incremental updates to try and beat one another, which might result in holding technology back. AMD is committed, according to its executives, to pushing the envelope of performance as much as it can every generation, regardless of the competition. Both CEO Dr. Lisa Su, and CTO Mark Papermaster, have said that they expected the timeline of the launch of their Zen 2 portfolio to intersect with a very competitive Intel 10nm product line. Despite this not being the case, the AMD executives stated they are still pushing ahead with their roadmap as planned.
| AMD 'Matisse' Ryzen 3000 Series CPUs | |||||||||||
| AnandTech | Cores Threads |
Base Freq |
Boost Freq |
L2 Cache |
L3 Cache |
PCIe 4.0 |
DDR4 | TDP | Price (SEP) |
||
| 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 |
AMD’s benchmark of choice, when showcasing the performance of its upcoming Matisse processors is Cinebench. Cinebench a floating point benchmark which the company has historically done very well on, and tends to probe the CPU FP performance as well as cache performance, although it ends up often not involving much of the memory subsystem.
Back at CES 2019 in January, AMD showed an un-named 8-core Zen 2 processor against Intel’s high-end 8-core processor, the i9-9900K, on Cinebench R15, where the systems scored about the same result, but with the AMD full system consuming around 1/3 or more less power. For Computex in May, AMD disclosed a lot of the eight and twelve-core details, along with how these chips compare in single and multi-threaded Cinebench R20 results.
AMD is stating that its new processors, when comparing across core counts, offer better single thread performance, better multi-thread performance, at a lower power and a much lower price point when it comes to CPU benchmarks.
When it comes to gaming, AMD is rather bullish on this front. At 1080p, comparing the Ryzen 7 2700X to the Ryzen 7 3800X, AMD is expecting anywhere from a +11% to a +34% increase in frame rates generation to generation.
When it comes to comparing gaming between AMD and Intel processors, AMD stuck to 1080p testing of popular titles, again comparing similar processors for core counts and pricing. In pretty much every comparison, it was a back and forth between the AMD product and the Intel product – AMD would win some, loses some, or draws in others. Here’s the $250 comparison as an example:
Performance in gaming in this case was designed to showcase the frequency and IPC improvements, rather than any benefits from PCIe 4.0. On the frequency side, AMD stated that despite the 7nm die shrink and higher resistivity of the pathways, they were able to extract a higher frequency out of the 7nm TSMC process compared to 14nm and 12nm from Global Foundries.
AMD also made commentary about the new L3 cache design, as it moves from 2 MB/core to 4 MB/core. Doubling the L3 cache, according to AMD, affords an additional +11% to +21% increase in performance at 1080p for gaming with a discrete GPU.
There are some new instructions on Zen 2 that would be able to assist in verifying these numbers.
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Teutorix - Tuesday, June 11, 2019 - link
If TDPs are accurate they should reflect power consumption.If a chip needs 95W cooling it's using 95W of power. The heat doesn't come out of nowhere.
zmatt - Tuesday, June 11, 2019 - link
I think technically it would be drawing a more than its TDP. The heat generated by electronics is waste due to the inefficiency of semi conductors. If you had a perfect conductor with zero resistance in a perfect world then it shouldn't make any heat. However the TDP cannot exceed power draw as that's where the heat comes from. How much TDP differs from power draw would depend on a lot of things such as what material the semiconductor is made or, silicon, germanium etc. And I'm sure design also factors in a great deal.If you read Gamers Nexus, they occasionally measure real power draw on systems, https://www.gamersnexus.net/hwreviews/3066-intel-i...
And you can see that draw massively exceeds TDP in some cases, especially at the high end. This makes sense, if semiconductors were only 10% efficient then they wouldn't perform nearly as well as they do.
Teutorix - Tuesday, June 11, 2019 - link
"I think technically it would be drawing a more than its TDP"Yeah, but if a chip is drawing more power than its TDP it is also producing more heat than its TDP. Making the TDP basically a lie.
"The heat generated by electronics is waste due to the inefficiency of semi conductors. If you had a perfect conductor with zero resistance in a perfect world then it shouldn't make any heat"
Essentially yes, there is a lower limit on power consumption but its many orders of magnitude below where we are today.
"How much TDP differs from power draw would depend on a lot of things such as what material the semiconductor is made or, silicon, germanium etc. And I'm sure design also factors in a great deal."
No. TDP = the "intended" thermal output of the device. The themal output is directly equal to the power input. There's nothing that will ever change that. If your chip is drawing 200W, its outputting 200W of heat, end of story.
Intel defines TDP at base clocks, but nobody expects a CPU to sit at base clocks even in extended workloads. So when you have a 9900k for example its TDP is 95W, but only when its at 3.6GHz. If you get up to its all core boost of 4.7 its suddenly draining 200W sustained assuming you have enough cooling.
Speaking of cooling. If you buy a 9900k with a 95W TDP you'd be forgiven for thinking that a hyper 212 with a max capacity of 180W would be more than capable of handling this chip. NOPE. Say goodbye to that 4.7GHz all core boost.
"If you read Gamers Nexus, they occasionally measure real power draw on systems, https://www.gamersnexus.net/hwreviews/3066-intel-i...
And you can see that draw massively exceeds TDP in some cases, especially at the high end. This makes sense, if semiconductors were only 10% efficient then they wouldn't perform nearly as well as they do."
None of that makes any difference. TDP is supposed to represent the cooling capacity needed for the chip. If a "95W" chip can't be sufficiently cooled by a 150W cooler there's a problem.
Both Intel and AMD need to start quoting TDPs that match the boost frequencies they use to market the chips.
Cooe - Tuesday, June 11, 2019 - link
... AMD DOES include boost in their TDP calculations (unlike Intel), and always have. They make their methodology for this calculation freely available & explicit.Spoelie - Wednesday, June 12, 2019 - link
Look at these power tables for 2700Xhttps://www.anandtech.com/show/12625/amd-second-ge...
=>You are only hitting 'TDP' figures at close to full loading, so "frequency max" is not limited by TDP but by the silicon.
=>Slightly lowering frequency *and voltage* really adds up the power savings over many cores. The load table of the 3700 will look on the whole different than for the 3600X. The 3700 will probably lose out in some medium threaded scenarios (not lightly and not heavily threaded)
Gastec - Wednesday, June 12, 2019 - link
That's not actually the real power consumption. Most likely you will get a 3700X with 70-75 W (according to the software app indications) but a bit more if tested with a multimeter. Add to that the inefficiency of the PSU, say 85-90%, and you have about 85 W of real power consumption. Somewhat better than my current 110W i7-860 or the 150+W Intel 9000 series ones I would say :)xrror - Monday, June 10, 2019 - link
funny you say that. AMD TDP and Intel TDP differ. I think.HEY IAN, does AMD still measure TDP as "real" (total) dissipation power or Intel's weaksauce "Typical" dissipation power?
Teutorix - Tuesday, June 11, 2019 - link
Intel rate TDP at base clocks. AMD do something a little more complex.Neither of them reflect real world power consumption for sustained workloads.
FreckledTrout - Tuesday, June 11, 2019 - link
In desktops they are simply starting points for the cooling solution needed. They do a lot better in the laptop/tablet space where TDP's make or break designs.Cooe - Tuesday, June 11, 2019 - link
Yes they do. A 2700X pulls almost exactly 105W under the kind of conditions you describe. Just because Intel's values are completely nonsense doesn't mean they all are.