I am using CPU-Z to test basic things about the J7. It reports an Exynos Octa 7580, 8 cores, 8x ARM Cortex-A53 @ 1.5GHz, r0p3, 28 nm.
At all times that I checked, only cores 0-3 are active, and cores 4-7 are stopped. Power saving is disabled.
Is there any way of activating all cores?
Is there any way of at least seeing all of them active, for testing purposes?
I have found a few posts around mentioning that it may be the way the phone+OS kernel keep temperature in check, but I am not sure it applies to J7, and if so, how to circumvent it.
PS: I find some times that my J7 is sluggish, so I wonder why would it have 4 processors idling if they could work (assuming the causes are processing several apps, which could be tackled by assigning different processors).