SPEC2006 - Full Results

The below chart might be a bit crowded but it it’s the only correct way to have a complete overview of the performance-power-efficiency triad of measurement metrics. The left axis dataset scales based on efficiency (Subtest total energy in joules / subtest SPECspeed score) and also includes the average active power usage (Watts) over the duration of the test. Here the shorter the bars the better the efficiency, while average power being a secondary metric but still should be below a certain value and well within the thermal envelope of a device. The right axis scales simply with the estimated SPECspeed score of the given test, the longer the bar the better the performance.

While the article is focused around the Kirin 970 improvements this is an invaluable opportunity to look back and the two last generations of devices from Qualcomm and Samsung. There is an immediate striking difference in the efficiency of the Snapdragon 820 and Snapdragon 835 across almost all subtests. The comparison between the Exynos 8890 and Snapdragon 820 variants of the S7 was an interesting debate at the time and we came to the conclusion the Exynos 8890 variant was the better unit as it offered longer battery life at higher performance. We see this represented in this dataset as well as the Exynos 8890 manages to have a measurable performance lead in a variety of tests while having higher energy efficiency, albeit a higher power envelope.

2017’s Galaxy S8 reversed this position as the Snapdragon 835 was clearly the better performing unit while having a slight battery life advantage. This efficiency delta can again be seen here as well as the Exynos 8895 isn’t able to compete with the lower power consumption of the Snapdragon 835, even though the performance differences between the Exynos M2 and Cortex A73 are a lot more of a wash than the previous generation’s battle between Exynos M1 and Kryo CPUs.

Switching over to the Kirin SoCs I included as far back as the Kirin 955 with the Cortex A72 as it was a very successful piece of silicon that definitely helped Huawei’s device portfolio for 2016. Remembering our coverage of the Cortex A73 microarchitecture we saw a lot of emphasis from ARM on the core’s floating point and memory subsystem performance. These claims can be easily confirmed when looking at the massive IPC gains in the memory access sensitive tests. When it comes to pure integer execution throughput the A72’s three-wide decoder as expected still managed to outpace the 2-wide unit on the A73 as seen in the 445.gobmk and 456.hmmer subtests.

The Kirin 960 was not able to always demonstrate ARM’s A73’s efficiency gains as again the more execution bound tests the Kirin 955 was equal or slightly more efficient. But again thanks to the new memory subsystem the A73 is able to well distance itself from the A72 with massive gains in 429.mcf, 433.milc, 450.soplex and 482.sphinx3. Again the power figures here are total platform active power so it’s also very possible that the Kirin 960’s memory controller could have a hefty part in the generational improvement.

The Kirin 970 doesn’t change the CPU IP, however we see the introduction of LPDDR4X on the memory controller side which will improve I/O power to the DRAM by lowering the voltage from 1.1V down to 0.6V. While performance should be the same power efficiency should thus be higher by the promised 20% that HiSilicon quotes from the switch to the TSMC 10nm process, plus some percentage due to LPDDR4X.

Performance indeed is within spitting distance of the Kirin 960, however it managed to be a few percentage points slower. On the power efficiency side we see large gains averaging up to 30% across the board. It looks that HiSilicon decided to invest all the process improvement into lowering overall power as the Kirin 970 manages to shave off a whole watt from the Kirin 960 both in integer and floating point benchmarks.

An interesting comparison here is the duel between the Snapdragon 835 and Kirin 970 – both A73 CPUs running at almost identical clocks, one manufactured on Samsung’s 10LPE process and the other on TSMC’s 10FF process. Again by making use of the various workload types we can extract information on the CPU and the memory sub-system. In 445.gobmk and 456.hmmer we see the Kirin have a very slight efficiency advantage at almost identical performance. This could be used as an indicator that TSMC’s process has a power advantage over Samsung’s process, something not too hard to imagine as the latter silicon was brought to market over half a year later.

When we however take a look at more memory bound tests we see the Snapdragon 835 overtake the Kirin 970 by ~20%. The biggest difference is in 429.mcf which is by far the most demanding memory test, and we see the Snapdragon 835 ahead by 32% in performance and a larger amount in efficiency. We can thus strongly assume that between the K970 and S835, Qualcomm has better and more efficient memory controller and subsystem implementation.

The memory subsystem generally seems to be the weak point of Samsung’s Exynos 8895. The M2 core remains competitive in execution bound tests however quickly falls behind in anything more memory demanding. The odd thing here is that I’m not sure if the reason here is memory controller inefficiency but rather something more related to the un-core of the M2 cluster. Firing up even integer power-viruses always have an enormous 1-core power overhead compared to the incremental power cost of additional threads on the remaining 3 cores. A hypothesis here is that given Samsung’s new Exynos 9810 makes use of a completely new cache hierarchy (all but confirmed a DynamiQ cluster) that the existing implementation in the M1 and M2 cores just didn’t see as much attention and design effort compared to the CPU core itself. Using a new efficient cluster design and continuing on improving the core might be how Samsung has managed to find a way (Gaining power and efficiency headroom) to double single-threaded performance in the Exynos 9810.

When overviewing IPC for SPEC2006, we see the Kirin 960 and Snapdragon 835 neck in neck, with the Kirin 970 being just slightly slower due to memory differences. The Exynos 8895 shows a 25% IPC uplift in CINT2006 and 21% uplift in CFP2006 whilst leading the A73 in overall IPC by a slight 3%.

The Snapdragon 820 still has good showing in terms of floating point performance thanks to Kryo’s four main “fat” execution pipelines can all handle integer as well as floating point operations. This theoretically should allow the core to have far more floating point execution power than ARM and Samsung’s cores, and is the explanation as to why 470.lbm sees such massive performance advantages on Kryo and brings up the overall IPC score.

The Final Overview

For a final overview of performance and efficiency we get to a mixed bag. If solely looking at the right axis with overall SPECspeed estimated results of CINT2006 and CFP2006, we see that performance hasn’t really moved much, if at all, over the last 2 generations. The Kirin 970 is a mere 10% faster than the Kirin 955 in CINT, over 2 years later. CFP sees larger gains over the A72 but again we come back to a small performance regression compared to the Kirin 960. If one would leave it at that then it’s understandable to raise the question as to what exactly is happening with Android SoC performance advancements.

For the most part, we’ve seen efficiency go up significantly in 2017. The Snapdragon 835 was a gigantic leap over the Snapdragon 820, doubling efficiency at a higher performance point in CINT and managing a 50% efficiency increase in CFP. The Exynos 8895 and Kirin 970 both managed to increase efficiency by 55% in CINT and the latter showed the same improvements in CFP.

This year’s SoCs have also seen a large decrease in average power usage. This bodes well for thermal throttling and flow low thermal envelope devices, as ARM had touted at the launch of the A73. The upcoming Snapdragon 845 and A75 cores promise no efficiency gains over the A73, so the improved performance comes with linear increase in power usage.

I’m also not too sure about Samsung’s Exynos 9810 claiming such large performance jumps and just hope that those peak 2.9GHz clocks don’t come with outrageous power figures just for the sake of benchmark battling with Apple. The Exynos’ 8890 2-core boost feature was in my opinion senseless as the performance benefit of the additional 300MHz was not worth the efficiency penalty (The above results were run at the full 2.6GHz, 2.3GHz is only 10% slower but 25% more efficient) and the whole thing probably had more to do with matching the Snapdragon 820’s scores in the flawed GeekBench 3.

I’m not too sure how to feel about that as I think the current TDPs of the Snapdragon 835 and Kirin 970 (in CPU workloads) are sweet spots that the industry should maintain as it just gives a better mobile experience to the average user, so I do really hope the Snapdragon 845 offers some tangible process improvements to counter-act the micro-architectural power increase as well as clock increases otherwise we’ll see power shooting up again above 2W. 

SPEC2006 - A Reintroduction For Mobile GPU Performance & Power
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  • Ratman6161 - Wednesday, January 24, 2018 - link

    Personally I think Samsung is in a great position...wheather you consider them "truly vertically integrated" or not. One thing to remember is that most often, Samsung flagship devices come in two variants. It's mostly in the US where we get the Qualcomm variants while elsewhere tends to get Exynos. The dual source is a great arrangement because every once in a while Qualcomm is going to turn out a something problematic like the Snapdragon 810. When that happens Samsung has the option to use its own which is what they did with the Galaxy S6/Note 5 generation which was Exynos only.

    Another point is: what do you consider "truly vertically integrated". The story cites Apple and Huewai but they don't actually manufacture their SOC's and neither does Qualcomm. I believe the Kirin SOC's are actually manufactured by TSMC while Apple and Qualcomm SOC's have at various times been actually manufactured in Samsung FABs. As far as I know, Samsung is the only company that even has the capability to design and also manufacture their own SOC. So in a way, you could say that my Samsung Note 5 is about the most vertically integrated phone there is, along with non-US versions of the S7 and S8 generations. In those cases you have a samsung SOC manufactured in a Samsung FAB in a Samsung phone with a Samsung screen etc. Don't make the mistake of thinking the whole world is just like us...they aren't. Also many of the screens for other brands are also of Samsung manufacture so you have to keep in mind that there is a lot more to the device than the SOC
  • fred666 - Monday, January 22, 2018 - link

    Huawei only uses HiSilicon SoCs? Nothing from Qualcomm?
  • Andrei Frumusanu - Monday, January 22, 2018 - link

    They've used Qualcomm chip-sets and still do use them in segments they can't fill with their own SoCs.
  • niva - Monday, January 22, 2018 - link

    So they still use QC chips, but unlike them, Samsung isn't vertically integrated because they use QC chips.

    Get out of here.
  • Dr. Swag - Monday, January 22, 2018 - link

    His point is Huawei only uses non-HiSilicon chips in price segments that they do not have SoCs for. Samsung, however, does sometimes use QC silicon even if they have SoCs that can fill that segment (e.g. Samsung uses the Snapdragon 835s even though they have the 8895).

    I'm not saying that I agree with Andrei's view, but there is a difference.
  • niva - Tuesday, January 23, 2018 - link

    I completely disagree with the assessment that Samsung is somehow not "as vertically integrated" as Huawei. Samsung is not just vertically integrated, it produces components for many other key players in the market. They have reasons why they CHOOSE not to use their SOCs in specific markets and areas. Some of the rationale behind those choices may be questioned, but it's a choice. I too think that the world would be a better place if they actually put their own chip designs into their phones and directly competed against Qualcom. That of course might be the end of Qualcom and a whole lot of other companies... Samsung can easily turn into a monopoly that suffocates the entire market, so it's not just veritcal, but horizontal integration. What Huawei has accomplished in short order is impressive, but isn't Huawei just another branch of the Chinese government at this point? Sure yeah, their country is more vertically integrated. Maybe that's the line to take to justify the statement...
  • levizx - Monday, February 26, 2018 - link

    No, it's not INTEGRATED because it doesn't prefer its own over outsourcing. Samsung Mobile department runs separately from its Semiconductor department which act as a contractor no different than Qualcomm.

    As for Huawei being a branch of the Chinese government, it's as true as Google being part of the US government. Stop spruiking conspiracy theory. I know for a fact their employees almost fully owns the company.
  • KarlKastor - Thursday, January 25, 2018 - link

    Well, that's not true. Huawei choose the Snapdragon 625 in the Nova. Why not use their own Kirin 600 Series? it is the same market segment.

    Samsung only opts for Snapdragon, where they have no own SoCs: all regions with CDMA2000 Networks.
    In all other regions, europe for example, they ship all smartphones frome the J- and A-Series to the S-Series and Note with their Exynos SoCs.
  • yslee - Tuesday, January 30, 2018 - link

    You keep on repeating that line, but where I am we have no CDMA2000 networks and still get Snapdragon Samsungs.
  • levizx - Monday, February 26, 2018 - link

    That's also not true, Samsung uses Snapdragon where there's no CDMA2000 as well. Huawei used to use VIA's 55nm CBP8.2D over Snapdragon.

    Mid-tier is not so indicative compared to higher end devices when it comes to, well everything. They may even outsource the ENTIRE DESIGN to a third party, and still proves nothing in particular. They might have chosen S625 because of supply issues which is completely reasonable. Same can not be applied to Samsung, since there's no such thing as supply issues when it comes to Exynos and Snapdragon.

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