Reply #1: I read some reviews for similar products (not exactly Sewell SW-31000) and, although

[struggle4progress]

some people really like converters like this, other folk seem unhappy about jerky outputs

So there might be an issue with signal speeds. You might want to look up your laptop specs to (say) see if the VGA is coming off the mobo, or off a gpu on pci, or off a gpu on pcie, and compare that with the usb bus -- and for that comparison you should probably figure out what generation usb your laptop has and whether the SW-31000 supports your full usb speed