I gig speed

Hey guys I have 1G service and with 2 Win10 PC's I get 1G profromance. Both systems are wired not WI-Fi.

Newest Xfinity phone/internet modem. I have no more inputs on  the modem to use my hard drive back  ups. I have a Netgear router with USB and the Hard Drives for Back up's, when I  use  that it cuts my speed in half  for d/l. Tried a switch but no where to plug the USA drives  in.

Any ideas and thanks