The AMD 2nd Gen Ryzen Deep Dive: The 2700X, 2700, 2600X, and 2600 Tested
by Ian Cutress on April 19, 2018 9:00 AM ESTPrecision Boost 2 and XFR2: Ensuring It Hertz More
One of the biggest changes for the new Ryzen-2000 series is in how the processor implements its turbo. Up until this point (except the recent APU launch), processors have relied on a step function implementation: the system determines how many threads are loaded, attempts to implement a specific frequency on those cores if possible, and then follows the look-up table relating thread count to frequency. AMD’s goal in Precision Boost 2 is to make this process more dynamic.
This image from AMD is how the feature is being represented: the system will determine how much of the power budget is still available, and turbo as much as possible until it hits one of the limiting factors. These factors can be any of, but not limited to, the following:
- Total chip peak power
- Individual core voltage/frequency response
- Thermal interactions between neighboring cores
- Power delivery limitations to individual cores/groups of cores
- Overall thermal performance
AMD’s new Ryzen Master 1.3 software, when used on a Ryzen 2000-series processor, has several indicators to determine what the limiting factors are. For the most part, the way the processor will boost and respond to the environment, will be transparent to the user.
The best way to test this in action, from my perspective, is to look at the power draw of the first generation and second generation Ryzen processors. We can examine the internal estimated power consumption of each core individually as thankfully AMD has left these registers exposed, to give the following data:
This is only the core consumption power, not the package power, which would include the DRAM controller, the Infinity Fabric, and the processor IO. This means we get numbers different to the rated TDP, but the danger here is that because the Ryzen 7 2700X has a 10W TDP higher than the Ryzen 7 1800X, where the 2700X draws more power it could seem as if that is the TDP response.
Just plotting the power consumption gives this graph:
Even in this case it is clear that the Ryzen 7 2700X is drawing more power, up to 20W more, for a variable threaded load. If we change the graph to be a function of peak power:
The results are not quite as clear: it would seem that the 1800X draws, as a percentage of peak power, more at low thread count, but the 2700X draws more at a middling thread count.
It is worth noting that the end result of Precision Boost 2 is two-fold: more performance, but also more power consumption. Users looking to place one of the lower powered processors into a small form factor system might look at disabling this feature and returning to a standard step-function response in order to keep the thermal capabilities in check.
A side note – despite the marketing name being called ‘Precision Boost 2’, the internal BIOS name is called ‘Core Performance Boost’. It sounds similar to Multi-Core Enhancement, which is a feature on some Intel motherboards designed to go above and beyond the turbo mechanism. However, this is just AMD’s standard PB2: disabling it will disable PB2. Initially we turned it off, thinking it was a motherboard manufacturer tool, only to throw away some testing because there is this odd disconnect between AMD’s engineers and AMD’s marketing.
Extended Frequency Range 2 (XFR2)
For the Ryzen 2000-series, AMD has changed what XFR does. In the previous generation it was applied on certain processors to allow them to boost above the maximum turbo frequency when the thermal situation was conducive to higher frequencies and higher voltage in low thread-count states. For this generation, it still relates to thermals, however the definition is applied to any core loading: if the CPU is under 60ºC, the processor can boost no matter what the loading is above its Precision Boost 2 frequency (so why not get a better PB2 implementation?). The core still has to be within a suitable voltage/frequency window to retain stability, however.
On certain motherboards, like the ASUS Crosshair VII Hero, there are additional options to assist XFR2 beyond AMD’s implementation. ASUS does not go into specific details, however I suspect it implements a more aggressive version, perhaps extending the voltage/frequency curve, raising the power limits, and/or adjusting the thermal limit.
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rocky12345 - Tuesday, April 24, 2018 - link
They ran all systems at both Intel's & AMD's listed specs as such AMD's memory was at 2933MHz on Zen+ & 2666MHz on Intel's Coffee lake 8700K,they did the same for the older gen parts as well and ran those at the spec's listed for them as well.There have been a few other media outlets that did the same thing and got the same results or very close to the same results. AMD's memory bandwidth as in memory controller seems to give more bandwidth than Intel's does at the same speed so with Intel not running at 3200MHz like most media outlets did maybe Intel loses a lot of performance because of that and AMD lost next to nothing from not going 3200MHz. It is all just guesses on my part at the moment.
Food for thought when Intel released the entire Coffee Lake line up they only released the z370 chip set which has full support for over clocking including the memory and almost all reviews were done with 3200MHz-3400MHz memory on the test beds even for the non K Coffee lakes CPU's. Maybe Intel knew this would happen and made sure all Coffee lakes looked their best in the reviews. For a few sites that retested once the lower tier chip sets were released the non K's using their rated memory speeds lost about 5%-7% performance in some cases a bit even more.
I am no fanboy of any company I just put out my opinions & theories that are based off of the information we are given by the companies and as well as the media sites.
Maxiking - Tuesday, April 24, 2018 - link
People never fail to amaze me, so you basically know nothing about the topic, yet you still managed to spit 4 paragraphs of mess, even made some "food for thought".Slower ram - performance regression unless you have big caches which is not the case of Intel nor AMD.
rocky12345 - Tuesday, April 24, 2018 - link
It seems pretty basic to me as to what was said in the post. It is not my problem if you do not under stand what myself and some others have said about this topic. Pretty simple slower memory less bandwidth which in turn will give less performance in memory intensive work loads such as most games. ALl you have to do is go and look at some benches in the reviews to see AMD has the upper hand when it comes to memory bandwidth even Hardware Unboxed was pretty surprised by how good AMD's memory controller when compared to Intel's. Yes Intel's can run memory at higher speeds than AMD but even with that said AMD does just fine. You are right about cache sizes neither has a overly large cache but AMD 's is bigger on the desktop class CPU's and that is most likely one of the reasons their bandwidth for memory is slightly better.Maxiking - Wednesday, April 25, 2018 - link
The raw bandwidth doesn't matter, it's cas latency what makes the difference here.https://www.anandtech.com/show/11857/memory-scalin...
https://imgur.com/MhqKfkf
With CL16, it doesn't look that much impressive, is it.
Now, lower the CL latencies to something more 2k18-ish, booom.
https://www.eteknix.com/memory-speed-large-impact-...
Another test
https://www.pcper.com/reviews/Processors/Ryzen-Mem...
Almost all the popular hw reviewers don't have a clue. They tell you to OC but do not explain why and what you should accomplish by overclocking. Imagine you have some bad hynix ram which can be barelly OC from 2666 to 3000mhz but you have to loose timing from CL15 for CL20 to get there.
mapesdhs - Monday, May 14, 2018 - link
schlock, the chips were run at official spec. Or are you saying it's AMD's fault that Intel doesn't officially support faster speeds? :D Also, GN showed that subtimings have become rather important for AMD CPUs; some mbds left on Auto for subtimings will make very good selections for them, giving a measurable performance advantage.peevee - Tuesday, April 24, 2018 - link
It is April 24th, and the page on X470 still states: "Technically the details of the chipset are also covered by the April 19th embargo, so we cannot mention exactly what makes them different to the X370 platform until then."jor5 - Tuesday, April 24, 2018 - link
The review is a shambles. They've gone to ground.coburn_c - Tuesday, April 24, 2018 - link
I have been wanting to read their take on x470..risa2000 - Wednesday, April 25, 2018 - link
It is my favorite page too.mpbello - Tuesday, April 24, 2018 - link
Today phoronix is reporting that after AMD's newest AGESA update their 2700X system is showing 10+% improvement on a number of benchmarks. It is unknown if on Windows the impact will be the same. But you see how all the many variables could explain the differences.