We have just released a major update for our Android app – A1 CPU Tool. While user interface stayed intact, we have completely redesigned frequency calculation algorithm, and added feature, that detects your Android device battery capacity. We have also extended option to hide even more frequencies and a little rearranged settings, so you can find them easier.
Now more about algorithm changes. The old (pre 2.0 CPU Tool) was looking at the your smartphone/device CPU as a single core CPU. That was not a problem, because majority (all?) of mobile multi-core CPUs ran on the particular frequency on all the cores simultaneously. And because of that, the results were still accurate and correct. The situation changed with a new ARM’s big.LITTLE architecture.
ARM big.LITTLE is a heterogeneous computing architecture developed by ARM Holdings, coupling relatively slower, low-power processor cores (LITTLE) with relatively more powerful and power-hungry ones (big). Typically, only one “side” or the other will be active at once, but since all cores have access to the same memory areas, workload can be swapped from big to LITTLE and back on the fly. The intention is to create a multi-core processor that can adjust better to dynamic computing needs and use less power than clock scaling alone. ARM’s marketing material promises up to a 75% savings in power usage for some activities. Wikipedia.
So we can not look at CPU in simplified manner we did in pre 2.0 version. For instance, take the Samsung new flahship device – Samsung Galaxy S6 edge plus. It contains two CPUs that can switch on and off, and even work simultaneously for some period of time, and even more – each of the CPUs run on the different frequencies – first is limited with 1.5 GHz (Cortex-A53) while second with 2.1 GHz (Cortex-A57), and not all lower frequencies are shared between them. For example, both A53 and A57 can run on 800 MHz, while only A53 runs on 400 MHz, but only A57 runs on 1300 MHz. You can view CPU cores for each frequency by accessing details window.
Also, we have added big.LITTLE value in Info tab. It indicates time when both of the CPUs are active. If your model/device does not show this value, then either it does not have two CPUs, or they do not run simultaneously.
What’s New in v2.0
New: Support for big.LITTLE CPU architecture
New: Detects battery max capacity mAh
New: Frequency details displays associated cores
New: Displays time, while both CPUs were active
Fixed: About tab shows correct CPU speed
Improved: Support for deca-core CPU Helio X20
Improved: Threshold of frequency grouping increased (up to 9.9%)
Improved: Toggle feature of average frequency refined