Camera Launching

I wanted also to have a closer look at CPU behaviour while using the phone's camera. First off, we start off by analyzing what happens when we launch the camera application.

Nothing much to report on the little cores, we only see some minor load on a couple of threads while the camera is running.

Most of the work when launching the camera was done by the big cluster. Here we see all 4 cores jumping into action. It's interesting to see that at these smaller time-scales we can observe how the CPU frequency lags behind the actual load on the cluster, as the frequency governor maintains a higher frequency for some time before falling back to the idle 800MHz.

Samsung seems to be able to parallelize well the camera application as this is again a sensible scenario that makes good usage of the 4.4 big.LITTLE topology of the SoC.

App: Play Store App Updates Camera: Still Snapshot
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  • lilmoe - Tuesday, September 1, 2015 - link

    "if the interest is high enough"

    :/ Really?
  • zaza - Saturday, September 5, 2015 - link

    Yes Please. It would be nice to see if the same or similar tests works on snaprdagon 810,801 and 615 and Mediatek chips, and intel SoC
  • erchni - Thursday, September 17, 2015 - link

    A follow-up with synthetic would be quite interesting.
  • aryonoco - Saturday, September 5, 2015 - link

    I just wanted to reiterate the point here an thank the author for this great piece of technical investigative journalism.

    Andrei, thank you for this work. It is hugely invaluable and insightful.
  • tipoo - Tuesday, September 1, 2015 - link

    Very interesting article. Seems like the mantra of "more cores on mobile are just marketing" was wrong in terms of Android, seems to dip into both four core big and little clusters pretty well. That puts the single thread performance having lagged behind the Apple A series (up until the S6 at least) in a new light, since it can in fact use the full multicore performance.
  • tipoo - Tuesday, September 1, 2015 - link

    *That is, barring gaming. More core Android functions do well with multithreading though.
  • jjj - Tuesday, September 1, 2015 - link

    In gaming there is a big advantage. By using mostly the small cores you allow for more TDP to go to the GPU. One more relevant thing would console ports in the next couple of years when mobile GPUs will catch up with consoles. The current consoles have 8 small cores and that fits just right with many small cores in Android.
  • retrospooty - Tuesday, September 1, 2015 - link

    Not really sure whos "mantra" that was. People that don't understand what the big.little architecture is like some angry Apple fans?
  • tipoo - Tuesday, September 1, 2015 - link

    Well sure, whoever they were, but it was a pretty common refrain for every 8 core SoC.
  • soccerballtux - Tuesday, September 1, 2015 - link

    for one, it was my mantra. I liked having 4 cores because 2 wasn't enough, but according to my hotplugging times, I only really need 3 for optimal experience most of the time

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