I purchased a nano-pi m3 to play with a cheap 8 core arm board and figured I would share my experiences. Much of what I found matches what is posted on this thread but not all.
I have not set up a dedicated SBC bench yet so I bring boards up in my mobile area since it is the only place with a spare HDMI cable. I use a good power supply with a long, crappy micro usb cable. A pine-64+ lives there under full load in a constant state of thermal limit. Let's see how long it takes to burn it out. But that is a different post, this one is about the M3.
Initial bringup was a breeze. Mount the optional HSF, flash the sdcard and plug it all in. It took three tries to get the fan plug on the right way as usual. Only two ways to plug it in but it always takes three tries. Not sure why.
The board came up just fine, idle temperatures were fine. Everything looked good. So down comes multi-miner for a bit of a stress test. Fire it up and temperatures quickly peak and it goes into thermal limit. Less than a minute later it crashes. I repeat this a few times before I see a pattern. Not needing the HDMI any more I move the board to my SBC pile with an Anker 60 watt, 6 port usb charger and short, high power USB charging cables. I inserted a USB doctor between the charger and the cable. I started it up and connected via SSH. Idle power consumption was a bit higher than the other SBC's. I start the miner and temperatures quickly peak and the board goes into thermal limit. USB doctor reports 1.5 amps of current draw.
Three and a half days later it is still running. I have no problems running the NanoPI M3 from the micro usb cable when I use a sensible power supply and sensible cable. It crashes and burns about as you would expect if you use a silly wimpy little cable you found in your sock drawer that you love since it is nice and long and gets from the wall wart behind your bed to your night stand where you charged your phone.
05:06:33 up 3 days, 16:51, 2 users, load average: 8.87, 8.88, 9.02
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
fa :0 :0 Wed12 ?xdm? 3days 0.24s /usr/bin/lxsession -s LXDE -e LXDE
root pts/0 x.x.x.x Wed12 1.00s 0.39s 0.01s w
root@NanoPi3:~# cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
My main concerns with this board are that is fails to gracefully slow down. It is alternating between 700, 800 and 1400 MHz. The pine64 I am abusing has settled down to alternating between 960 and 1080 MHz. This feels a bit more sensible than what the M3 is doing. I know it is only software to fix it so I have started down the path of building my own image. I have set up the cross tool chain and built everything so now all I have to do is tweak it..
I am a bit disappointed with the FA provided HSF. The fan is loud and ineffective and the processor overheats. I suppose this is better than the HSF offered with the Pine64 (none). The heat sinks that come with the Odroid's are much better. My C2 does thermal limit a bit running the miner but that is with the board in the optional plastic box.
Probably my biggest annoyance is the lack of a 64 bit OS. I really wanted the 64 bit extensions for mining / boinc. Though, given the weak cooling I suspect the lower performing kernel is a blessing in disguise.