Why do Android phones use hundreds of times less power than an SBC?
by Jason_25 from LinuxQuestions.org on (#4WB32)
I have noticed since the beginning how bad SBC computers are with power usage. They are are, to the very last one, hugely inefficient devices.
The reason I ask this today is because I had an incident with my last custom mobile device and am thinking of building a new one.
One of the lowest power SBC computers, the Raspberry Pi Zero uses over 100mA at idle with nothing connected. It seems low, but this is actually garbage power consumption. It is far too weak to browse the modern internet, but it would drain the largest phone battery in just a few hours! That in my eyes makes it one of the worst computers imaginable.
Let's get this out of the way: my Android phone uses 3mA at idle. 3mA x 4.2v = 12.6mV. This is while it is running and listening actively for texts and calls. It has over 2 weeks of actual battery life with a 2500 mah battery. Theoretically it has over a month of battery life.
Let's speculate on why this is:
Is Linux the problem? Android phones run a Linux kernel so this seems unlikely.
Is the SBC market the problem? People have incredibly low expectations of these devices afterall when they think the Pi Zero for example is "low power".
Is the price the problem? I can't find an efficient SBC for ANY price.
Is the processor design scale the problem? I believe the Lattepanda I am using now has a 16nm CPU but still sucks down 500mA at 4.2v.
Are "Sleep states" the problem? This seems unlikely because the Lattepanda I am using uses tens of times more power than my Android phone even when the Lattepanda is shut down!
Are built in peripherals the problem? Unlikely because the Pi Zero has almost none but uses more power than a remote control car.
Is a secretive "hardware cabal" that sets out to make any custom battery powered device impossible the problem? This I can believe in because of how difficult it is to save power. The manufacturers of smartphones have razor thin margins already. If it was viable to build your own they would all go out of business tomorrow.
In Conclusion:
You can see I am in no hurry to build another custom mobile device when SBC manufacturers are not helping me out in the least. Any "new" SBC is just going to be another phoned-in, useless, power draining beast of a board. You would think as long as I have been working on this problem I would have a solution but the power draw is still a mystery to me.
The reason I ask this today is because I had an incident with my last custom mobile device and am thinking of building a new one.
One of the lowest power SBC computers, the Raspberry Pi Zero uses over 100mA at idle with nothing connected. It seems low, but this is actually garbage power consumption. It is far too weak to browse the modern internet, but it would drain the largest phone battery in just a few hours! That in my eyes makes it one of the worst computers imaginable.
Let's get this out of the way: my Android phone uses 3mA at idle. 3mA x 4.2v = 12.6mV. This is while it is running and listening actively for texts and calls. It has over 2 weeks of actual battery life with a 2500 mah battery. Theoretically it has over a month of battery life.
Let's speculate on why this is:
Is Linux the problem? Android phones run a Linux kernel so this seems unlikely.
Is the SBC market the problem? People have incredibly low expectations of these devices afterall when they think the Pi Zero for example is "low power".
Is the price the problem? I can't find an efficient SBC for ANY price.
Is the processor design scale the problem? I believe the Lattepanda I am using now has a 16nm CPU but still sucks down 500mA at 4.2v.
Are "Sleep states" the problem? This seems unlikely because the Lattepanda I am using uses tens of times more power than my Android phone even when the Lattepanda is shut down!
Are built in peripherals the problem? Unlikely because the Pi Zero has almost none but uses more power than a remote control car.
Is a secretive "hardware cabal" that sets out to make any custom battery powered device impossible the problem? This I can believe in because of how difficult it is to save power. The manufacturers of smartphones have razor thin margins already. If it was viable to build your own they would all go out of business tomorrow.
In Conclusion:
You can see I am in no hurry to build another custom mobile device when SBC manufacturers are not helping me out in the least. Any "new" SBC is just going to be another phoned-in, useless, power draining beast of a board. You would think as long as I have been working on this problem I would have a solution but the power draw is still a mystery to me.