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
Play Store Open & Scroll
The little cores all have significant load placed onto them. It looks like the app multi-threads well in this scenario and the little threads are well fitted to accomodate the load that is placed onto them.
Surpsingly, we also see the big CPUs having some continuous load. The app launch itself triggers the big cluster to go to full speed of 2.1GHz and migrate threads onto all 4 CPUs. Scrolling through the page also loads at least 1 significant big thread. The CPU's frequency remains quite moderate though as we only see some small bursts to up to 1GHz while the rest of the time the big cores idle on the minimum 800MHz frequency.
Overall, the Play Store app also seems to be optimized and aimed for 4-core designs. Here big.LITTLE seems to work well as we see a mix of small threads with a mix of big threads running concurrently on both clusters.
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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 SoCerchni - 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