Well, if you both use the connection between the router and the ISP that could be a bottleneck.
Now do a speedtest (for example: http://www.speedtest.net/, many more available) and see the results. Doing it twice simultaneously should half the speed. Roommates share a room and the capacity of the line.
Kees
I have an hard wire installed into a wifi router on back where there is a cable port. My roommate say that the cable slow down her speed on her labtop when she on the wifi internet?

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