CPU and GPU Capacitance and Leakage Current

Which Khadas SBC do you use?

**Khadas Vim3 Pro**

Which system do you use? Android, Ubuntu, OOWOW or others?


Which version of system do you use? Khadas official images, self built images, or others?

**Khadas official images with linux kernel 4.9**

Please describe your issue below:

**I want to estimate the CPU clusters and GPU power. May I know the CPU clusters and GPU capacitance and leakage current? **

Hi @Yujie_Zhang
There haven’t been any such measurements, there is no support for such voltage measurement on the SoC.

@Electr1 Capacitance and leakage current are platform-specific constants. Can we get them in hardware-specific documents?

By the way, do you know how to get the GPU or CPU theoretical voltage corresponding to different frequencies?

Yes, you need to check the device tree for the operational points.

You can extract it on your board itself.

dtc -I dtb -O dts /boot/dtb/amlogic/kvim3.dtb

Thanks, @Electr1 I got the result. May I know whether the CPU or GPU voltage would change or not if I supply 12V instead of 5V to the Khadas Vim3 Pro board? If so, where could I figure out the value of the voltage?

No, they would not. They are moderated by onboard regulators.

@Electr1 Then the current of CPU or GPU core would not change, right? But when I supplied the board using 12V, the current for the whole board was decreased :rofl: . Do you know why?

@Yujie_Zhang you have asked for CPU and GPU supplied voltage, you did not mention anything about board voltage or current. The device is only rated based on dynamic power consumption, and supported voltage ranges.

More voltage would mean less amperage for same power consumption.

@Electr1 So, whether the overall board supply voltage is 15V or 5V, the supplied voltage to the CPU and GPU remains constant. In the case of a 15V supply voltage, the board current decreases. Does this affect the current flowing through the CPU and GPU?

Not at all, board current is not the same as cpu/gpu current, that’s why mentioned it is regulated.