CPU Performance & Efficiency: SPEC2006

We’re moving on to SPEC2006, analysing the new single-threaded performance of the new Cortex-A77 cores. As the new CPU is running at the same clock as the A76-derived design of the Snapdragon 855, any improvements we’ll be seeing today are likely due to the IPC improvements of the core, the doubled L3 cache, as well as the enhancements to the memory controllers and memory subsystem of the chip.

Disclaimer About Power Figures Today:

The power figures presented today were captured using the same methodology we generally use on commercial devices, however this year we’ve noted a large discrepancy between figures reported by the QRD865’s fuel-gauge and the actual power consumption of the device. Generally, we’ve noted that there’s a discrepancy factor of roughly 3x. We’ve reached out to Qualcomm and they confirmed in a very quick testing that there’s a discrepancy of >2.5x. Furthermore, the QRD865 phones this year again suffered from excessive idle power figures of >1.3W.

I’ve attempted to compensate the data as best I could, however the figures published today are merely preliminary and of lower confidence than usual. For what it’s worth, last year, the QRD855 data was within 5% of the commercial phones’ measurements. We’ll be naturally re-testing everything once we get our hands on final commercial devices.

In the SPECint2006 suite, we’re seeing some noticeable performance improvements across the board, with some benchmarks posting some larger than expected increases. The biggest improvements are seen in the memory intensive workloads. 429.mcf is DRAM latency bound and sees a massive improvement of up to 46% compared to the Snapdragon 855.

What’s interesting to see is that some execution bound benchmarks such as 456.hmmer seeing a 28% upgrade. The A77 has an added 4th ALU which represents a 33% throughput increase in simple integer operations, which I don’t doubt is a major reason for the improvements seen here.

The improvements aren’t across the board, with 400.perlbench in particular seeing even a slight degradation for some reason. 403.gcc also saw a smaller 12% increase – it’s likely these benchmarks are bound by other aspects of the microarchitecture.

The power consumption and energy efficiency, if the numbers are correct, roughly match our expectations of the microarchitecture. Power has gone up with performance, but because of the higher performance and smaller runtime of the workloads, energy usage has remained roughly flat. Actually in several tests it’s actually improved in terms of efficiency when compared to the Snapdragon 855, but we’ll have to wait on commercial devices in order to make some definitive conclusions here.

In the SPECfp2006 suite, we’re seeing also seeing some very varied improvements. The biggest change happened to 470.lbm which has a very big hot loop and is memory bandwidth hungry. I think the A77’s new MOP-cache here would help a lot in regards to the instruction throughput, and the improved memory subsystem makes the massive 65% performance jump possible.

Arm actually had advertised IPC improvements of ~25% and ~35% for the int and FP suite of SPEC2006. On the int side, we’re indeed hitting 25% on the Snapdragon 865, compared to the S855, however on the FP side we’re a bit short as the increase falls in at around 29%. The performance increases here strongly depend on the SoC and particular on the memory subsystem, compared to the Kirin 990’s A76 implementation the increases here are only 20% and 24%, but HiSilicon’s chip also has a stronger memory subsystem which allows it to gain quite more performance over the A76’s in the S855.

The overall results for SPEC2006 are very good for the Snapdragon 865. Performance is exactly where Qualcomm advertised it would land at, and we’re seeing a 25% increase in SPECint2006 and a 29% in SPECfp2006. On the integer side, the A77 still trails Apple’s Monsoon cores in the A11, but the new Arm design now has been able to trounce it in the FP suite. We’re still a bit far away from the microarchitectures catching up to Apple’s latest designs, but if Arm keeps up this 25-30% yearly improvement rate, we should be getting there in a few more iterations.

The power and energy efficiency figures, again, taken with a grain of salt, are also very much in line with expectations. Power has slightly increased with performance this generation, however due to the performance increase, energy efficiency has remained relatively flat, or has even seen a slight improvement.

Introduction & Specifications System Performance
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  • joms_us - Monday, December 16, 2019 - link

    Right, he even claimed a 2015 Apple A9 is faster than Skylake and Ryzen processors today. Only a complete !Diot will believe this claim. Reply
  • Quantumz0d - Monday, December 16, 2019 - link

    You should see AT forum. A thread has been dedicated to discuss this BS fanboyism and outcome was Apple won. Reply
  • Andrei Frumusanu - Monday, December 16, 2019 - link

    x86 emulation on Arm has absolutely nothing to do with any topic discussed here or QC vs Apple performance. I'm sick and tired of your tirades here as nothing you say remains technical or on point to the matter.

    The experience I have, when dismissing any other aspects such as iOS's super slow animations, is that the iPhones are far ahead in performance of any Android device out there, which is very much what the benchmark depict.
    Reply
  • Quantumz0d - Monday, December 16, 2019 - link

    Did I mention anything from your article on QC vs x86 ? I was replying to a comment on "Revolutionary" performance of A series vs x86. And then you claimed it as nonsensical point of x86 on ARM.

    So "super slow animations" & "far ahead". What do you mean by that ? An iPhone X vs a 11 Pro will exhibit the launching speed, then loading speed differences same as 835 vs 855 which can be observed. Everything ApplePro guy did a massive video of iPhones across multiple A series iterations which is the ONLY way a user can see the performance improvement.

    But when Android vs iOS you are saying iPhone animation speeds are super slow yet the benches show much lead..So how is the user seeing the far ahead in performance out there when OP7 Pro vs iPhone 11 Pro Max, like iPhone is still faster as you claim but in reality user is seeing same ?
    Reply
  • Andrei Frumusanu - Monday, December 16, 2019 - link

    Apparently I'm able say that because I'm able to differentiate between CPU performance, raw performance, and "platform performance".

    CPU performance is clear cut on where we're at and if you're still arguing this then I have no interest in discussing this.

    Raw performance is what I would call things that are not actually affected by the OS, web content *is* far faster on the latest iPhone than on Androids, that's a fact. Among this is actual real applications, when Civilization came to iOS the developers notably commented on the performance being essentially almost as good as desktop devices, the performance is equal to x86 laptops or better: https://www.anandtech.com/show/13661/the-2018-appl...

    And finally, the platform experience includes stuff like the very slow animations. I expect this is a big part as to what you regard as being part of your "experience" and "reality". I even complained about this in the iPhone 11 review as I stated that I feel the hardware is being held back by the software here.

    Now here's what might blow your mind: I can both state that Apple's CPUs are far superior at the same time as stating that the Android experience might be faster, because both statements are very much correct.
    Reply
  • Quantumz0d - Monday, December 16, 2019 - link

    Okay thanks for that clarity on Raw performance and other breakdowns like CPU, Platform. Yes I can also see that Web performance on A series has always been faster vs Androids.

    I forgot about that article. Good read, and on Civ 6 port however it lacks the GFX options. I would also mention that TFlops cannot be even compared within same company. Like Vega 64 is 12TFs vs a 5700XT at 9TFs, latter completely wrecks the former in majority except for the compute loads utlizing HBM. I know you mentioned the FP16 and other aspects of the figure in opening, just saying as many people just take that aspect. Esp the new Xbox SX and Console as a whole (They add the CPU too into that figure)

    And finally. Yes ARM scales in normal browsing, small tasks vs x86 laptops which majority of the people nowadays are doing (colleagues don't even use PCs) but for higher performance and other workloads ARM cannot cut it at all.

    Plus I'd also add these x86 laptop parts throttle a lot incl. Macbooks obv because they are skimping on cooling them for thinness so their consistency isn't there as well just like A series.
    Reply
  • joms_us - Monday, December 16, 2019 - link

    When I look at the comparisons here, I look only for Android vs. Android or Apple vs. Apple. Comparing them with different OSes and more so primitive tools is a worthless approach. Firstly, the results need to be normalized, one Soc is showing lead while sucking more power than the other. Secondly, the bloated scores of Apple Soc here does not represent real-world results. Most Android phones with SD855 are faster if not the same than iPhone 11. Reply
  • Andrei Frumusanu - Monday, December 16, 2019 - link

    > Comparing them with different OSes and more so primitive tools is a worthless approach.

    SPEC is a native apples-to-apples comparison. The web benchmarks and the 3D benchmarks are apples-to-apples interpreted or abstracted, same-workload comparisons.
    All the tests here are directly comparable - the tests which aren't and which rely on OS specific APIs, such as PCMark, obviously don't have the Apple data.

    > Firstly, the results need to be normalized, one Soc is showing lead while sucking more power than the other.

    That's a very stupid rationale. If you were to follow that logic you'd have to normalise little cores up in performance as well because they suck much less power.
    Reply
  • joms_us - Monday, December 16, 2019 - link

    > SPEC is a native apples-to-apples comparison.

    Stop right there, Apple vs. Apple only

    > The web benchmarks and the 3D benchmarks are apples-to-apples interpreted or abstracted, same-workload comparisons.
    All the tests here are directly comparable - the tests which aren't and which rely on OS specific APIs, such as PCMark, obviously don't have the Apple data.

    How? Just like Geekbench, different compilers are used. Different distribution of loads are made.
    My Ryzen 2700 can finished 5 full GB run as fast as one full GB run in an iPhone and yet the single core score of iPhone is higher than any Ryzen. You are showing Apple A13 (LOL A13 is faster than the fastest AMD or Intel chip) using Jurassic Spec benchmark?

    Talk about dreams vs. reality.

    > That's a very stupid rationale. If you were to follow that logic you'd have to normalise little cores up in performance as well because they suck much less power.

    We are talking about efficiency here, your beloved Apple chip is sucking twice the power than SD855 or SD865 per workload.

    Have you ever load a consumer website or run an consumer app with these phones side-by-side? Don't tell they are not using cpu or memory resources. They are, they are doing most if not all of the workloads on the charts here. While your chart if showing Apple has twice the performance vs SD865, the phone doesn't tell lies. A bloated benchmark score does not translate to real-world result.

    It is time to stop this worthless propaganda that Android SoC is inferior than Apple and the laughable IPC king (iPhone chip is faster than desktop processors).

    Until iPhone can play Crysis smoother than even low end laptops, this BS claim that it is the fastest chip should stop.
    Reply
  • Quantumz0d - Monday, December 16, 2019 - link

    Agreed.

    It really feels like a propaganda every single article on CPU Apple gets super limelight because of these benches on a closed walled garden platform from OS to HW to Repair.

    The power consumption of A series processors deteriorating the battery was nicely thrown under the rug by Apple throttling bs. They even added the latest throttle switch for XS series. But yea no one cares. Apple's deeppockets allow top lawyers in their hands to manipulate every thing.

    The consumer app part. Its perfect use case since we never see any of the Android phones lag as interpreted here due to the dominance of A series by 2-3x folds and in real life nothing is observable. And comparing that to the x86 Desktop machines with proper OS and a computing usecases like Blender, Vray, MATLAB, Compliation, MIPS of Compression and decompression, Decode/Encoding and superior Filesystem support and socketed / Standardized HW (PCIe, I/O options), Virtualization and Gaming, DRAM scaling choice (user can buy whatever memory they want or any HW as its obvious)..this whole thing screams bs. It would be better if the highlight is mentioned on benches and realwork might differ but its not the case at all.

    The worst is spineless corporate agenda of allowing Chinese CPC to harvest every bit from their Cloud data Center in China allowing the subversion and anti liberty. A.k.a Anti American principles.
    Reply

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