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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mapesdhs - Saturday, April 21, 2018 - link
Not an argument.0ldman79 - Thursday, April 19, 2018 - link
In the real world we have to choose depending on features and performance while constrained by a budget.For intellectual discussion and better understanding of the chips and architecture we need direct comparison.
Both arguments work for entirely different reasons. I rarely have the budget for high end Intel. I'm also into overclocking and run VM, so the only way I hit both of those is to run AMD.
I've also got a few apps that really take advantage of AVX2 and AVX512, which even the Ryzen gets monstrously stomped by Intel.
If you judge by a single metric you're missing the big picture. Everything is a compromise.
Ninjawithagun - Thursday, April 19, 2018 - link
Actually, the comparison between the 2600X (not 2700X) and the 8700K is based upon multiple metrics, not just one.Ninjawithagun - Thursday, April 19, 2018 - link
Once again incorrect. Cost vs. Cost is only one of many factors to consider, but is not a main one, especially if the competition has a processor of equal quality for much less cost. Comparing an Intel 6 core/12 thread CPU to an AMD 8 cores/16 thread CPU makes absolutely no sense if you are measuring cost vs. performance. Your argument makes no sense, sorry.LurkingSince97 - Thursday, April 19, 2018 - link
Once again incorrect. Cost vs Cost is the primary factor for a buyer on a budget. It is the main one.Case in point, if I can get a 2600X for the same price as a much slower Intel chip, it is obviously better.
Comparing a $300+ chip to a $200+ one makes absolurely no sense if you are measuring cost vs. performance. Your argument makes no sense, sorry.
See what I did there? Your argument (and the one above) are BS. You are either a troll, or have a serious intellectual disability. Price, performance, and implementation details (core count) are all independent dimensions and you can look at any of them from the perspective of the other.
Price just happens to be the constraint that most shoppers have to start with. They can vary the other parameters, within the price constraint.
A others with more money might instead lock in a performance / feature set requirement and _then_ consider price, but that is the minority.
fallaha56 - Thursday, April 19, 2018 - link
Well saidI suggested the chap apply his own facile argument and compare threadripper to the 8700k...
gglaw - Saturday, April 21, 2018 - link
They compared multiple "qualities" of processors between two Ryzen generations and CL. If you want to look at them core for core, is it that hard to shift your eyes 3 lines up to see the next line of results? Do you want them to exclude the 2700X since there isn't a consumer level CL to match it?LurkingSince97 - Thursday, April 19, 2018 - link
Price and absolute performance are paramount. Comparing at raw architecture levels is interesting but less important.In the real world, there are consumers who are not that price sensitive, in which case they only care about a top end part that is within their range. They don't care if it is 10 core/ 20 thread vs 8 core /16 thread or 6 core 12 thread -- they care about the raw performance for what they need, and are usually willing to go up in cost somewhat for that performance (including mobo/ram costs). This is the sort of consumer I am today.
There are then others who are price sensitive and have a budget. For these people the price tag is paramount. The flaw with this review (and most in general) is that it does not include mobo / ram / etc costs and often just looks at the CPU price alone. For someone budget conscious they have to carefully consider whether saving $100 on a CPU or $50 on a mobo can give them the ability to spend that on say, a better GPU or nicer monitor. For those, comparing products by price point is way more important than comparing them by architecture. This is the sort of consumer I was when I was a poor college student / gamer that had to part together my own systems with very limited budgets.
As a tech geek, I am always interested in the core-for-core or clock-for-clock comparison, but in the real world for purchasing decisions it doesn't matter if a Ryzen with 6 cores/12 threads at 3Ghz is faster or slower than an Intel chip with 6 cores/12 threads at 3Ghz. In the end, they can have different core counts, threads, and Ghz -- all that matters is the actual performance.
Targon - Monday, April 23, 2018 - link
In the case of Ryzen, you can use the same motherboard from the first generation to the second, or the third, or the fourth(in 2020). You may not get all the features, but they will work, and CPU cost is the only thing needed since you already have the other components.Actual performance is the correct focus, but game performance isn't the same as rendering performance, or for those who tend to have 8+ programs open as a part of their normal work environment. Just saying "performance" ignores that what you use your computer for isn't necessarily the same as what other people use their computer(s) for.
Targon - Monday, April 23, 2018 - link
That is why they use different game benchmarks. Some do make use of more cores/threads, and others make use of other design differences between different products. Price vs. performance is a very valid comparison based on workload, not just games, but in other tasks. You could have higher core count processors with lower clock speeds at the same price point, even when looking at Intel. 6-core lower speed, or 4-core higher speed at the same price point. Which does better for the tasks you personally care about? Intel 8700K vs. AMD 2700X is the fair comparison, while you will compare the 2600 to the i5, again, due to the price point. When you look at the performance results, you SHOULD in theory, see that these chips match up in terms of performance for the price, though AMD tends to have an advantage these days in multi-threaded tasks, while Intel tends to do better in lightly threaded workloads due to clock speeds.