AllWinner A80 Octa Core big.LITTLE Processor CPU Usage Under Various Loads in Android 4.4 (Video)

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Allwinner A80 is one of the few octa core processors featuring ARM’s big.LITTLE technology currently available on the market. The processor comes with four ARM Cortex A15 (big) cores, and four ARM Cortex A7 (LITTLE) core, and tasks will be scheduled to different processor depending on the load to optimize power consumption on mobile devices. However, earlier big.LITTLE processors like Samsung Exynos 5410 has some serious limitations, as they only supported “cluster migration” meaning you could only use the Cortex A7 cluster or Cortex A15 cluster at any given time, so Exynos 5410 could only make use of four cores at most due to hardware limitations. They also used to be two software implementations: In-kernel Switching (IKS) and Global Task Scheduling (GTS). The former could only handle one type of core at the same, and the latter, which I believe is now used in all new devices, can handle any combination of cores, so an octa core big.LITTLE SoC can indeed make use of all its eight cores.

Antutu_3D_CPU_Usage
To make sure it was the case with Allwinner A80 SoC, I did a little test using PVRMonitor app on Tronsmart Draco AW80 mini PC. I did this test to check all eight cores can be used, and to see which cores and how many cores are used for various loads such as multi-tab web browsing and gaming. The scheduler was set to Performance with No-frills CPU Control app.

I’ve run Antutu, the Android stock Browser with multiple tabs open, and Beach Buggy Blitz 3D racing games in the video above. The takeaway for this short test is that Allwinner A80 can run its eight cores simultaneously, but in typical use, it’s rare to see more than four cores used simultaneously. I forgot to include video playback in the video, so I tried to play 4K videos and H.265 videos with Kodi 14, and normally (hardware video decoding) only two Cortex A15 are used (around 30% per core),  and when software video decoding is needed (H.265), at most four cores are used, so it looks like Kodi has not been optimized yet to make full use of octa systems, at least on Allwinner A80.

So in Android mini PCs, there’s usually very little gain from an octa core processor instead of a quad core processor, unless you run apps that can make use of all cores such as video transcoding apps, or you want it convert it into a Linux mini PC to compile software or run a server.

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Study Shows Octa Core Processors Bring Little Over Quad Core Processors in Mobile DevicesTronsmart Draco AW80 Review - Is this the mini-PC to beat in 2015? - AndroidPCReviewLes performances du AllWinner A80 en vidéocnxsoftRafael duarte Recent comment authors
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ntux
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ntux

Hi,

How was the software playback of h265 files (1080p or 4k)? Was it smooth, and how was the cpu usage?

I’m considering buying this box, however rk3288 ones have better hardware decoding capabilities, but if A80 manages software decoding well, this should not be a big deal for me.

Thanks!

anon
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anon

@ntux
If buying a new ARM system at this point in time, why would you not get a system with a hardware H.265 decoder?

And the only SoC that seems to have real support for both H.265 and 2160p/4k/UHD is the Amlogic S812… Every other lacks proper support for either one.

Rafael duarte
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Rafael duarte

How much can do A80 when all the cores are tuned and the CPU and GPU with software optimization.
For this type of SoC,all the app they must be optimized too,I believed so,even games.
For the GPU power vr I think at this stage hasn,’t been yet optimized,still in works
For the 8 cores, same CPU or different it shows in reality that they are powerful
Lollipop has been optimized for this matters, even kit kat.

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[…] Première constatation du testeur, si il est possible que la puce fasse tourner ses 8 coeurs en parallèle, il est très rare de voir plus de 4 coeurs en simultané. Un test de lecture vidéo 4K sous Kodi 14 montrent que seuls 2 coeurs Cortex-A15 sont sollicités à environ 30% de leurs performances. Ceci s’explique par le fait que la puce graphique du A80 est parfaitement capable de gérer cela matériellement. […]

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[…] fact, CNX-Software did a test of various apps which showed the core use in real time. During video playback using Kodi 14, there were only a few times when all cores were being used. […]

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[…] Last year, I found out, that more powerful cores may be more important than many cores, when I tested Allwinner A80 processor with PVRMonitor to check CPU usage per core in real-time, and in Antutu, while Browsing the web or playing games, […]