I bought the banana Pi M3 because it had Sata and a gigabit Ethernet connection. I planed to create a Nas using an external raid enclosure connected via Sata. Come to find out that the USB to SATA bridge is terrible and will never surpass USB 2.0 transfer speeds. Not to mention that my raid is not even recognized when connected via Sata.
I’ve accepted the fact that I would have to connect the raid via USB and live with no greater than 60 megabytes per second transfer speeds theoretical. Imagine my surprise when the maximum file transfer speeds achieved are 100 megabits per second or ~12MBps. It was then that I realized that the gigabit Ethernet port was functioning at one hundred megabits per second. I’ve tried ubuntu mate 15.10 and raspbian images. Although ethtool list the adapter as supporting 1000baset-fd, the device Auto negotiates at 100 and when I try to force it to 1000 using mii-tool, I get an error saying that it is not supported.
I just installed 2016-04-25-ubuntu-mate-16.04_Xenial_gpu_mpv_1080p_bt-bpi-m3_beta-sd-emmc.img.zip and now the eth0 shows 1000baset.
Now my problem is how to expand the ext4 file system on the microSD card. With that image installed there only ~300MB available on the partition created when I apply the image to the microSD card. I tried booting using the 15.10 Ubuntu Mate installed on the eMMC and using gparted to expand the filesystem. After that the BPI-M3 would not boot the SDcard.
No way. Theoretical USB2.0 is limited to 40MB/s max, on this board only one of the 2 USB host ports is used and every external available USB receptacle and the ultra slow USB-to-SATA bridge are behind an internal USB hub. M3 is the worst choice for any NAS EVER: http://linux-sunxi.org/Banana_Pi_M3#SATA
There are two other boards around (Orange Pi Plus and Cubietruck Plus) that use also this crappy USB-to-SATA bridge but there a dedicated USB host port is used to connect to this ultra slow chip.