This article introduced how to adjust the VCC-CPUX voltage of the BPI-M2+ with replacing a register of power circuit.
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WARNING!
With any hardware change or component soldering.
You will LOST all warranty of your Banana Pi!
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When I did something system image build and test tasks for the BPI-M2+ with Allwinner H3 before it on stock last year, I have received a Engineer Sample (ES) form SINOVOIP, the manufacturer of Banana Pi.
The Banana Pi Community Forum have received a lot of reports of the too high VCC-CPUX voltage causing horrible heat issue from other developers.
There is a easy to measure the VCC-CPUX voltage of your BPI-M2+.
This picture shows the Test Point (TP: VCPU) of VCC-CPUX.
If you get a result like me, Congratulation! You got a ES. (R. I. P. the warranty
Okay, the next step is replace the reference register in the feedback circuit of the voltage regulator.
I have no 0402 register in my component library, so I use the 0805. (I’m sorry for that.
Before:
After:
And it works. 🙂
According to the AW’s whitepaper H3 should work at 1.008GHz max_freq, but I tested ok with the 1.2GHz sys_config. Lucky~
This is the cpuinfo_cur_freq result of running cpuburn-a7 (https://github.com/ssvb/cpuburn-arm/raw/master/cpuburn-a7.S) and corekeeper.sh.
The idle CPU temperature is about 15 degrees Celsius lower than work at 1.4 V.