Same problem here. Using Geomagic for Solidworks plugin. Can scan, then during the "auto surface" operation, it goes to not responding. Task manager shows memory usage at less than 3GB of the 16GB installed. CPU usage at about 18% on 4 of the 8 cores shown for an i7 processor (likely it is not using hyperthreading, so the even numbered CPUs are not used)
New video card (NVIDIA P1000) with driver recommended from SW RX
Added memory (to 32GB)
Updated Solidworks to 2017 SP5
I've had the same issue using a Hexagon arm. Solidworks almost never uses files over 10mb, but I've had cloud data files easily 50mb (best case) to as much as 600mb. Geomagic and 3D Systems have told me the slowness is on the Solidworks side. I have had luck trying to combine and simplify my files as quickly as possible - as well as only using an amount of data appropriate for the part (obviously, high accuracy = high data usage = high file size). I generally keep a giant "raw" file, then save-as a working document. In Geomagic, I opt not to keep the original data when creating a mesh. Try to get that 250mb file down to 50mb as quick as possible.
Also I have noticed the "not responding" tag is inaccurate. It'll come back as long as I don't push any buttons.