The AMD 2nd Gen Ryzen Deep Dive: The 2700X, 2700, 2600X, and 2600 Tested
by Ian Cutress on April 19, 2018 9:00 AM ESTTranslating to IPC: All This for 3%?
Contrary to popular belief, increasing IPC is difficult. Attempt to ensure that each execution port is fed every cycle requires having wide decoders, large out-of-order queues, fast caches, and the right execution port configuration. It might sound easy to pile it all on, however both physics and economics get in the way: the chip still has to be thermally efficient and it has to make money for the company. Every generational design update will go for what is called the ‘low-hanging fruit’: the identified changes that give the most gain for the smallest effort. Usually reducing cache latency is not always the easiest task, and for non-semiconductor engineers (myself included), it sounds like a lot of work for a small gain.
For our IPC testing, we use the following rules. Each CPU is allocated four cores, without extra threading, and power modes are disabled such that the cores run at a specific frequency only. The DRAM is set to what the processor supports, so in the case of the new CPUs, that is DDR4-2933, and the previous generation at DDR4-2666. I have recently seen threads which dispute if this is fair: this is an IPC test, not an instruction efficiency test. The DRAM official support is part of the hardware specifications, just as much as the size of the caches or the number of execution ports. Running the two CPUs at the same DRAM frequency gives an unfair advantage to one of them: either a bigger overclock/underclock, and deviates from the intended design.
So in our test, we take the new Ryzen 7 2700X, the first generation Ryzen 7 1800X, and the pre-Zen Bristol Ridge based A12-9800, which is based on the AM4 platform and uses DDR4. We set each processors at four cores, no multi-threading, and 3.0 GHz, then ran through some of our tests.
For this graph we have rooted the first generation Ryzen 7 1800X as our 100% marker, with the blue columns as the Ryzen 7 2700X. The problem with trying to identify a 3% IPC increase is that 3% could easily fall within the noise of a benchmark run: if the cache is not fully set before the run, it could encounter different performance. Shown above, a good number of tests fall in that +/- 2% range.
However, for compute heavy tasks, there are 3-4% benefits: Corona, LuxMark, CineBench and GeekBench are the ones here. We haven’t included the GeekBench sub-test results in the graph above, but most of those fall into the 2-5% category for gains.
If we take out Cinebench R15 nT result and the Geekbench memory tests, the average of all of the tests comes out to a +3.1% gain for the new Ryzen 2700X. That sounds bang on the money for what AMD stated it would do.
Cycling back to that Cinebench R15 nT result that showed a 22% gain. We also had some other IPC testing done at 3.0 GHz but with 8C/16T (which we couldn’t compare to Bristol Ridge), and a few other tests also showed 20%+ gains. This is probably a sign that AMD might have also adjusted how it manages its simultaneous multi-threading. This requires further testing.
AMD’s Overall 10% Increase
With some of the benefits of the 12LP manufacturing process, a few editors internally have questioned exactly why AMD hasn’t redesigned certain elements of the microarchitecture to take advantage. Ultimately it would appear that the ‘free’ frequency boost is worth just putting the same design in – as mentioned previously, the 12LP design is based on 14LPP with performance bump improvements. In the past it might not have been mentioned as a separate product line. So pushing through the same design is an easy win, allowing the teams to focus on the next major core redesign.
That all being said, AMD has previously already stated its intentions for the Zen+ core design – rolling back to CES at the beginning of the year, AMD stated that they wanted Zen+ and future products to go above and beyond the ‘industry standard’ of a 7-8% performance gain each year.
Clearly 3% IPC is not enough, so AMD is combining the performance gain with the +250 MHz increase, which is about another 6% peak frequency, with better turbo performance with Precision Boost 2 / XFR 2. This is about 10%, on paper at least. Benchmarks to follow.
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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.