The Mobile CPU Core-Count Debate: Analyzing The Real World
by Andrei Frumusanu on September 1, 2015 8:00 AM EST- Posted in
- Smartphones
- CPUs
- Mobile
- SoCs
Camera Still Snapshot
This time we take a picture with the stock camera. While most processing should be handled by hardware accelerators such as the ISP, scalers and JPEG hardware unit, there's still work to be done in terms of saving the image to the storage as well as handling other metadata as well as generating the thumbnail for the camera interface and gallery.
The actual snapshot causes a large spike on the small cores, again overloading them to up to a run-queue depth of up to 6.
The big cores see some minor activity that seems to happen after the actual picture has been captured, so we might be looking at the file saving process.
Overall the picture capture sees quite a surprising peak in terms of the run-queue depth, fully utilizing up to 6 CPUs on the system.
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modulusshift - Tuesday, September 1, 2015 - link
Heck yes. And of course I'm interested if anything like this is even remotely possible for Apple hardware, though likely it would require jailbreaks, at least.Andrei Frumusanu - Tuesday, September 1, 2015 - link
Unfortunately basically none of the metrics measured here would be possible to extract from an iOS device.TylerGrunter - Tuesday, September 1, 2015 - link
Add one more vote for the follow up with synthetics.I would also want to see how the multitasking compares with the Snapdragons as they use the different frequency and voltage planes per core instead of the big.LITTLE.
But I guess that would be better to see with the SD 820, as the 810 uses big.LITTLE. Consider it a request for when it comes!
tuxRoller - Wednesday, September 2, 2015 - link
Big.little can use multiple planes for either cluster. The issue is purely implementation, tmk.TylerGrunter - Wednesday, September 2, 2015 - link
big.LITTLE can be use different planes for each cluster but same for all cores in each cluster, Qualcomm SoCs can use different planes for each core, that's the difference and it's a big one.https://www.qualcomm.com/news/onq/2013/10/25/power...
I'm not sure that can be done in big.LITTLE.
tuxRoller - Friday, September 4, 2015 - link
I remember that but that doesn't say that big.LITTLE can't keep each core on its own power plane just that the implementations haven't.soccerballtux - Tuesday, September 1, 2015 - link
to balance everything out-- meh, that doesn't interest me. most of the time I'm concerned with battery life and every-day performance. Android isn't a huge gaming device so absolute performance doesn't interest me.porphyr - Tuesday, September 1, 2015 - link
Please do!ppi - Tuesday, September 1, 2015 - link
Go ahead. This is one of the most interesting performance digging on this site since the random-write speeds on SSDs.jospoortvliet - Friday, September 4, 2015 - link
Yes, this was an awesome and interesting read.