Modem CM1000v2 and nether router R6020. Will a switch between modem and computer work?

[McGyverdave43]

My netgear router AC750 model R6020 limits my 1GBps internet speed. will a switch between the modem and computer work? The modem has only one port.

[FURRYe38]

You may need a newer R series router to support 1Gb ISP speeds. Also ensure your ethernet adapters are supporting of 1000mpbs connection rates. 

[plemans]

What modem is it? 

If its a modem only device, you can't put a switch between the modem and the router.