1gb modem but 50 mbs speed with every ethernet

It would be a godsend if someone could fix this.

1. I have 1gb modem and service. It even says it on my PC. However when downloading games/updates I max at 50mbs

2. I have tried multiple cat6 lan cables, straight from the modem, so that's not the problem.

3. My GF gets nearly triple my speeds on wifi. Granted her PC is right next to the modem/router.