mb 12" retina: random disconnects with external usb3.1typeC disc "sandisk extreme 900 960GB"

hello,

i recently bought an external disc of 960GB "sandisk extreme 900" with usb3.1typC connection. the disc has no other port.

it is directly connected to my macbook 12" retina with usb3.1typeC port, and i experienced random disconnects, without physically moving either the macbook or the external disc. the disconnects happen only, when a copy is going on, i am copying 100 or 200GB.

the plug is connected properly and does not show up anymore at the finder or in the apple harddisctool app - after the disconnect.

when i reboot 3 times, it shows up with error "drive my be damaged, you can read but not write, format this disc"

when i test the drive on my imac 27", i dont get discconnects. but then i use a different cable: "usb3.1typeC to usb3.0"

- is this model "sandisk extreme 900" compatible with the mb 12" retina?

- is there enough power supply by the mb 12" retina? e.g. when 30% power is left, i unplug the powercable and plug the external sandisk into the mb - then i wonder if the external disc could get enough power?

thanks!