AMD's Ryzen 9 6900HS Rembrandt Benchmarked: Zen3+ Power and Performance Scaling
by Dr. Ian Cutress on March 1, 2022 9:30 AM ESTCPU Tests: SPEC Performance
SPEC2017 is a series of standardized tests used to probe the overall performance between different systems, different architectures, different microarchitectures, and setups. The code has to be compiled, and then the results can be submitted to an online database for comparison. It covers a range of integer and floating point workloads, and can be very optimized for each CPU, so it is important to check how the benchmarks are being compiled and run.
For compilers, we use LLVM both for C/C++ and Fortran tests, and for Fortran we’re using the Flang compiler. The rationale of using LLVM over GCC is better cross-platform comparisons to platforms that have only have LLVM support and future articles where we’ll investigate this aspect more. We’re not considering closed-sourced compilers such as MSVC or ICC.
clang version 10.0.0
clang version 7.0.1 (ssh://git@github.com/flang-compiler/flang-driver.git
24bd54da5c41af04838bbe7b68f830840d47fc03)-Ofast -fomit-frame-pointer
-march=x86-64
-mtune=core-avx2
-mfma -mavx -mavx2
Our compiler flags are straightforward, with basic –Ofast and relevant ISA switches to allow for AVX2 instructions. We decided to build our SPEC binaries on AVX2, which puts a limit on Haswell as how old we can go before the testing will fall over. This also means we don’t have AVX512 binaries, primarily because in order to get the best performance, the AVX-512 intrinsic should be packed by a proper expert, as with our AVX-512 benchmark. All of the major vendors, AMD, Intel, and Arm, all support the way in which we are testing SPEC.
To note, the requirements for the SPEC licence state that any benchmark results from SPEC have to be labeled ‘estimated’ until they are verified on the SPEC website as a meaningful representation of the expected performance. This is most often done by the big companies and OEMs to showcase performance to customers, however is quite over the top for what we do as reviewers.
In the single threaded test, the jump over the regular Zen 3 Ryzen mobile variant (5980HS) at the same power is quite substantial: +9.6% on integer performance and +14.1% on floating point. The move from DDR4 to DDR5 is quite substantial in that regard, and it’s seen in a lot of our upcoming benchmarks.
We didn’t see any change from 35 W to 45 W to 65 W in our AMD testing as the power consumption of the chip in single threaded workloads did not exceed 24 W, however we did see performance difference in Intel’s Alder Lake going from 45 W to 65 W, showcasing how much power the core can consume.
But if we compared that to Intel’s latest Alder Lake offerings, there’s a deficit in both categories – even though our lowest data here is at 45 W, we can see that the 45 W testing of the previous generation Intel also beats the 6900HS at SPECint (but AMD wins in SPECfp). This is something that carries through to multi-threaded performance.
For Multi-Threaded performance, we only saw the slightest improvement from AMD moving up to 65 W, perhaps showcasing that the hardware is limited in other ways than just power and the uplift from DDR4 to DDR5. In any event, at 35 W, AMD still surpasses what the previous generation Intel i9-11980HK can provide at 65 W.
But if we compare it to Intel’s latest Alder Lake processors, featuring 6 performance cores and 8 efficiency cores, we now have 20 threads up against AMD’s 16 threads. If we compare 45 W to 45 W, Intel has a +14.0% lead in integer and a +13.3% lead in floating point, despite the 20% increase in threads. With Intel introducing this dual tier performance with hybrid SoCs, multi-threaded performance is going to be a combination of fast+slow and it all comes down to how the system can divide up the work.
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ingwe - Tuesday, March 1, 2022 - link
While I understand not looking at battery life in this, not looking at graphics is a big miss._abit - Tuesday, March 1, 2022 - link
Back to pimping intel ever so gentlySarahKerrigan - Tuesday, March 1, 2022 - link
In 35/45W laptops, including this one, a dGPU will generally be present, making it a little moot. I expect more of a focus on graphics in the 15W review.Kangal - Wednesday, March 2, 2022 - link
Not at all.Most laptops (+80%) are below 45W TDP and they don't have a dGPU, and rely on the iGPU. It's a shame AMD has dragged their heels in this segment. For that reason, RDNA-2 is a substantial upgrade for most laptop users, but if you want a thick, heavy, Gaming Laptop then you are better off with the (12th-gen) Intel CPU and Nvidia dGPU (GeForce 30).
Besides, I see AMD's tech as eras:
2015-era, 16nm, Zen1, Vega Graphics
2018-era, 8nm, Zen2, RDNA-1 graphics
2021-era, 6nm, Zen3, RDNA-2 graphics
2024-era, 4nm, Zen4, RDNA-3 graphics
...roughly speaking (obviously years don't align)
And someone earlier asked how do these different GPU architectures compare. It's hard to do a true Potatoes-to-Potatoes comparison. However, from my understanding of the latest options it goes:
Qualcomm Adreno 7th-gen > Apple Graphics M1 > PowerVr IMG B-series > AMD RDNA-2 > Nvidia Ampere > ARM Mali Valhall 4th-gen > Intel Xe 1st-gen.
...obviously even the latest 4nm Adreno 730 when maxed out at 10W TDP, is no match against an older 8nm RTX 3050 that is thermal limited to only 100W TDP.
cbutters - Tuesday, March 1, 2022 - link
I hate to say it, but I agree.... this is literally one of the biggest step increases in iGPU performance; EVER, and nobody is talking about it. Why? Does Intel have input on how these articles are written? Or does it contribute to the ad revenue and people are wary of disrupting that? Its literally the MOST interesting thing about this CPU.JasonMZW20 - Tuesday, March 1, 2022 - link
Mostly because these systems ship with dGPUs. The iGPU in mobile Ryzen 6000 is a nice upgrade and simply demolishes anything Intel offers, currently.The mainstream 15-28W article should focus on iGPU, as these won't ship with dGPUs, usually. This is the meat of the market, and a good iGPU is critical to a good experience.
AMD's mobile strategy seems to be a quick-iterative design. Renoir and Cezanne were nearly on top of each other, as Cezanne came back from the fab just as Renoir shipped. So, with mobile Ryzen 6000/Rembrandt, AMD offers a new iGPU+(LP)DDR5 rather than new CPU cores, plus SoC optimizations overall.
The one thing that bothers me about the RDNA2 iGPU is that AMD disables an entire shader array in the 6600U instead of simply turning off 2 WGPs (4 CUs). So, there's a sharp performance drop between the two models and 6600U will be the primary volume seller, I think. 12 CUs to 6 CUs, instead of 12 -> 8 -> 6.
DannyH246 - Tuesday, March 1, 2022 - link
Honestly it’s been like this for a while now. Just go to the home page and count how many Intel marketing articles we’ve had over the last couple months. Now we get a half arsed joke of a review like this on AMD hardware. Obviously in Intel’s pocket.29a - Tuesday, March 1, 2022 - link
Typical half assed AMD article.DannyH246 - Tuesday, March 1, 2022 - link
Next headline article on www.IntelTech.com….Breaking news Intel CEO Gelsinger breaks wind.
Qasar - Wednesday, March 2, 2022 - link
DannyH246 i see you cry about this all the time, if anandtech is that bad, WHY do you keep coming here ? is it just to whine and cry?? im sure you will just reply with some sort of BS, but it HAS been stated before, there are times when most articles are intel, and others are AMD, its just the way the cycles go.