RE: power consumption
I'd like to share what I had measured on MK808 (RK3066 based) and CX919 II (RK3188 based, the one I have is a full RK3188, not cost reduced RK3188T version.)
I used a digital ampere meter to perform the measurement.
Test condition: Android 4.3 and 4.4, using Antutu full test suite.
Supply voltage 5 Volt.
MK808, idle:650mA, CPU stress test: 1250 mA, graphics test: 2000mA
Note under the latter two, CPU and RAM chips generate tremendous amount of heat (beyond factory heatsink), I retrofit with big one with fan cooling.
2A is a big stretch on the power supply, power cable, and the USB-based power connector.
In brief, I would suggest stay away from this old design.
CX919 II: idle: 450mA, CPU stress test: 900mA, graphics test: 1350mA.
Note: CPU is much cooler (RK3188 is 28nm geometry.) However, the build is too cheap even to include a real heatsink.
Suggest to use a large heatsink but active fan cooling may be avoided.
Power supply is okayish as it is.
My suggestion: use a CX919 II, great benefit when compare with the old RK3066 based.
Note: iAstrohub under Linux may not be that stressing on the CPU at all. I doubt any load is used on Graphics (Mali 400.)