Qualcomm SoC & ARMv8 custom core discussions

Discussion in 'Mobile Devices and SoCs' started by Nebuchadnezzar, Jan 20, 2015.

  1. french toast

    Veteran

    Joined:
    Jan 5, 2012
    Messages:
    1,667
    Likes Received:
    9
    Location:
    Leicestershire - England
    Thermal throttling!?? I thought these phones had 'liquid cooling' :smile: also I've seen other videos from LBS on YouTube which do a crude throttling check and the 820 in the mi5 throttles less through certain benchmark runs than the exynos 8890 with its cooling setup.

    Samsung might have gimped the s820 for some reason or it may need some optimisation, but one thing is clear, in other phones running the same processor it's real world day to day usage is barely any faster than last year's processors (outside graphics), which has to be considered a fail when you consider the new manufacturing process, I really do wish Qualcomm had gone for a cortex a72 setup, hexacore with 2 a72s @2.5-2.7 GHz and 4 a53s @ 1.8-2.0 GHz, in a smartphone form factor I actually think such a setup would be perfect on 14/16nm.

    I also could see another array of a35s possibly clocked @ 1.2ghz in a setup similar to media techs upcoming x20, but the scheduler would have to be pretty good I imagine to see real benefits of using so many cores, whether so many threads used concurrently would improve performance on android remains to be seen, but I could see legitimate power saving scenarios of using each cluster for its optimised workload.

    I do however like what Samsung has done with the exynos 8890, in boosting 2 cores to 2.6 GHz in certain workloads, I wonder if cortex a72 could be setup in such a way? Or is that a result of the special circuity in the M1 cores?

    Back on topic, is this performance stumbling block of kryo a result of its unbalanced design towards floating point performance over INT? I like what they have done with the memory performance, trying to keep the resources fed, just wish they had gone as wide as something like a a57/a72, even if it meant dropping the clock speed and a slight regression in floating point performance.
     
  2. ToTTenTranz

    Legend Veteran Subscriber

    Joined:
    Jul 7, 2008
    Messages:
    10,001
    Likes Received:
    4,573
    Antutu scores prove nothing. There are lots of 8890 vs S820 comparisons on the web showing the former at an arm's length from the later in 3dmark and gfxbench.
     
  3. Nebuchadnezzar

    Legend

    Joined:
    Feb 10, 2002
    Messages:
    974
    Likes Received:
    141
    Location:
    Luxembourg
    My guess is that Kryo is simply slow. I'll have both models soon enough for an apples to apples comparison so it's safe to say I'll go balls deep into that review.
     
    newbieforever and french toast like this.
  4. Raqia

    Regular

    Joined:
    Oct 31, 2003
    Messages:
    508
    Likes Received:
    18
    It'd be interesting to see a comparison of the clock throttled 820 vs a Snapdragon 652 (maybe the Xiaomi Mi5 vs the Samsung A9) to have a better feel about the Kryo vs the A72 core. Most of the benchmark wins are probably due to the higher clock speed excellent memory sub-scores of the kryo. I'd be curious to know more about the disabled L3 situation on the 820 as well, namely if it makes a come back w/ the 825, 830 or what have you.

    Edit:

    Looks like the Mi5 compares well to the US Galaxy S7.

    http://arstechnica.com/gadgets/2016...-hard-to-argue-with-305-for-a-snapdragon-820/

    Seems fishy, may some serious throttling is going on outside a few select benches for the S820 S7, but perhaps that's all the thermal envelope allows for.
     
    #244 Raqia, Mar 19, 2016
    Last edited: Mar 22, 2016
  5. fehu

    Veteran Regular

    Joined:
    Nov 15, 2006
    Messages:
    1,462
    Likes Received:
    395
    Location:
    Somewhere over the ocean
    before long the mi 5 pro will be released with upped clocks
     
  6. Raqia

    Regular

    Joined:
    Oct 31, 2003
    Messages:
    508
    Likes Received:
    18
    Ars made a correction:

    The Exynos seems impressively efficient in the wifi and WebGL tests, however it may be the case the Snapdragon is downloading more data or rendering extra frames per unit time; this isn't free! Hopefully someone will get to the bottom of this.
     
Loading...

Share This Page

  • About Us

    Beyond3D has been around for over a decade and prides itself on being the best place on the web for in-depth, technically-driven discussion and analysis of 3D graphics hardware. If you love pixels and transistors, you've come to the right place!

    Beyond3D is proudly published by GPU Tools Ltd.
Loading...